I. SUB-ORDER MARSUPIATA.--THE KANGAROO AND WOMBAT FAMILIES…

I. SUB-ORDER MARSUPIATA.--THE KANGAROO AND WOMBAT FAMILIES

THE GREAT KANGAROO--Captain Cook and the Great Kangaroo--Habitat--Appearance of the Animal--Marsupials separated from the other Mammalian Orders, and why (Footnote)--Gestation and Birth of Young (Footnote)--Mode of Running--The Short Fore Limbs--The Marsupium, or Pouch--Head--Dentition--Peculiarities in the Teeth--Hind Extremities--Foot--Great Claw--How the Erect Position is maintained--Whence their Jumping Power is derived--Other Skeletal Peculiarities--Kangaroo Hunts--Becoming Rarer--Mode of Attack and Defence--Hands--Bones of the Fore Limbs--Skull--Stomach--Circulation of Blood--Peculiarity in Young--Nervous System not fully developed--Brain--The Baby Kangaroo in the Pouch--THE HARE KANGAROO--THE GREAT ROCK KANGAROO--THE RED KANGAROO--THE BRUSH KANGAROO--THE BRUSH-TAILED ROCK KANGAROO--THE COMMON TREE KANGAROO--THE KANGAROO-RATS--Characteristics--THE RAT-TAILED HYPSIPRYMNUS--Description--THE WOMBAT FAMILY--THE WOMBAT--Peculiarities--Description--Habits--Teeth--Skeleton.

I. THE KANGAROO FAMILY.[81]--THE GREAT KANGAROO.[82]

In the year A.D. 1770, the great circumnavigator, Captain Cook, was on the coast of New South Wales repairing his ship, and a party of sailors were sent on land, to procure food for the sick. They saw an animal whose description tempted Cook himself, and also Mr. Banks (afterwards Sir Joseph Banks), to land and go in pursuit of it the next day. The animal was seen in company with others of its kind, and its short front limbs, great hind legs, and huge tail, and the tremendous hops it made in its very fleet course, quite bore out the statements of the astonished crew. They had seen, for the first time, the Great Kangaroo in its wild condition and on its own ground. Soon afterwards a specimen was shot, and notes were made about the creature, and some skins were brought over to Europe.

The animal has now become familiar to the civilised world. It is, however, gradually receding before the Australian colonist and squatter; but formerly it roamed all over the plains of New South Wales, Southern and Western Australia, Queensland, and Van Diemen’s Land, with only the aborigines for its enemies. It is called Bundaary and Bullucur by the natives of the Liverpool range and Murray, and the name Kangaroo is a mistaken native one.

On looking at one of the Great Kangaroos in some menagerie or zoological garden, the first peculiarities that strike the eye are its small fore limbs, its very large and long hind ones, and the great and thick tail. The smallness of the head, which has rather long ears, and a long dusky brown muzzle, the length of the body, and the comfortable grey-brown, thick, shortish fur, are then noticed. But the principal fact which impresses all these things upon the visitor, is that the female may have a little Kangaroo with its head poked out of a kind of pouch in the under part of the body. Sometimes the little one jumps out and gets in again if it is frightened, and the old one moves, hops, and jumps about, with its portable nursery, with the greatest ease.[83]

Sometimes the Kangaroos may be seen feeding, and then the awkwardness of their gait becomes evident; for the small fore legs and curious paws are on or very close to the ground, whilst the back part of the body is raised up by the long hind legs, and, as it were, balanced by the great tail. These hind legs seem to do nearly all the running, or rather jumping, both being used together; and the tail is of use in supporting the long body when the animal suddenly raises itself up straight, and squats on its hind quarters. The small front legs then appear quite stunted, and the ears stick up, and the small head is held straight. But in slow walking, the fore feet are placed on the ground, and the animal rests on them whilst it brings the long hind quarters forward and outside them. Evidently the senses of hearing and sight are very acute; but they are used to warn the animal of danger, rather than to urge it to attack, for it is a feeder on herbs, leaves, and grass, and often may be seen reclining and moving its jaws, as if it were chewing the cud after a fashion.

When moving with great velocity, the Kangaroo depends upon the hind limbs alone, bounding along with great ease, over ten, fifteen, or more feet at a jump. Its body is then carried almost horizontally, and the tail is stuck out as if to balance it.

If the short fore limbs are examined, they will be noticed to be able to do a great deal in the way of holding, clasping, and turning things about, and they are used in patting the little ones, and in embracing and cleaning them. The five digits, or fingers, have a very free movement, and the fore arm can twist and turn like that of the higher animals; that is to say, it is capable of pronation and supination. The first digit, or thumb, has two joints (phalanges), and the other four have three; and the five curved claws (the third and fourth being large) are useful weapons of offence. But they and the fingers are often used for very different purposes, and they have, in the female, to open the curious pouch for the young ones, and to place them there. There is an evident relation between the arrangement of the bones of the wrist and this necessary office or function. The marsupium, or pouch, is a kind of inbending of the skin of the lower part of the belly, and is moist and naked inside. In it, in the females, are the nipples of the mammary glands, and to these the very young Kangaroos[84] hang on for a long time, before they see the outer world. They are put in there by the mother, when they are just born, and when very small and not perfectly formed. They grow there, and after a while, leave the nipple when they think fit. As this pouch, with its contents, would drag upon the mother, it is kept from doing so, more or less, by two bones which are found amongst the muscles of the lower part of the body, and which are attached to the front or pubic bones of the pelvis. They are called marsupial bones. They exist also in the males, but they have no open pouch, for it is, as it were, turned outwards, and contains part of the reproductive organs.

The head is long, and is remarkable for the long nose, and large full eyes, with eyelashes, for the Kangaroo is not nocturnal in its habits, like most of the Marsupials. The upper lip is split, the end of the nose or muffle is naked or hairy according to the kind, and the brain-case is small. The nostrils are at the side of the end of the muzzle, and are slit-like and oblique, and there are bristly “smellers” to the fleshy lips and chin. A slender tongue is sometimes seen for an instant whilst the Kangaroo is feeding, and if the bones of the jaws be examined, the angle, or lower part of the back of the lower jaw, will be found to be turned inwards.

The long jaws have not very many teeth, and there are two large lower front ones, or lower incisors, which project in a line with the lower jaw; they are horizontal and more or less pointed, but have an outer and inner cutting edge. The upper incisors, six in number, or three on each side of the middle line, are placed on the pre-maxillary bone, and they work up and down. They are broad and have the cutting edge below, and the outer one, on each side, is broad, grooved, and complicated by one or two folds of its enamel, which are continued from the outer side of the tooth obliquely forward and inward. There is a space or diastema behind the incisors. There are four premolars, one on each side of both jaws, and then follow four molar teeth above and below and on both sides of the mouth. The dental formula is thus--Incisors, (3-3)/(1-1); premolars, (1-1)/(1-1); molars, (4-4)/(4-4) = 28. There are no canine teeth in the adults, but their germs may be found in the very young Kangaroos. As the Kangaroo is a vegetable feeder, and delights in grass, leaves, and herbs, its teeth are eminently of a non-carnivorous kind. It may be remarked that when the mouth is closed, the cutting edges of the upper incisors come against the outer cutting edge of the long front teeth of the lower jaw. The true molars increase in size from front backwards; and the crown of each molar is squarish, but is longer than broad, and it has two principal cross ridges, which, when not worn, are tall, and have sharp edges. Besides these, there are two other transverse ridges which are smaller and not so tall. One of these is on the front part of the tooth, and the other on the hinder (in the upper molars only). Then there is a long ridge which connects the cross ones. They are all covered with enamel. When the tooth is worn, we find it presenting, according to Mr. Waterhouse,[85] two powerful loops or folds. On comparing these teeth with those of the herbivorous mammalia already noticed, a remarkable difference will be seen.

The hinder extremities consist of a nearly straight, long, cylindrical bone, the femur, which has a hemispherical joint head, and a large trochanter, which reaches above the joint; of two leg bones--the tibia, which is prismatic above and cylindrical below, but with only a slight inner ankle projection, and the fibula, which is distinct but thinned and concave in its lower half, where it is close and attached to the other bone, and forms the outer ankle projection. To these are added the bones of the ankle-joint and the clawed toes. The Kangaroo being a great jumper, and having a great tendon, the analogue of the tendo achillis of man, has a powerful projecting process of the hinder ankle bone for its attachment. But the great length of the foot is produced by the size of the fourth and fifth or two outer toes, and especially of the fourth, which often reaches a foot in length, including the metatarsal bone behind, and the pointed claw in front. The great claw looks like a long hoof, is three-sided and sharp-pointed like a bayonet, and with it the animal stabs and rips open the body of its opponent.[86] The outer claw is very small, and there is no great toe (or first), but the second and third are long and slender, and are united in a common skin, so as to look like a single toe with a double nail, the hair coming to the roots of it. The long narrow foot is nearly as long as the leg bones, and is admirably adapted for jumping forwards, as well as sideways, and for supporting, when the legs are widely separated, the weight of the erect body. The body in that position has the leg bones straight, the thigh bones oblique, and the pelvis and spine erect, the great tail being a prop behind. Owen remarks that in man it is the massive and expanded muscles of the back of the pelvis and upper part of the thigh, or the gluteal muscles,[87] which are the chief structures in maintaining the erect posture. But in the Kangaroo, the narrow bones of the haunch could not afford attachment to great gluteal muscles; so a muscle which is but slightly formed in man, and is called the little psoas, is greatly developed in the Kangaroo, and has evidently the power of maintaining the erect posture, although it is situate within the body and in front of the spine. The great jumping power is due to the leverage of the ankle and long toes, and the muscles which supply the tendon already mentioned, and others which have the same office. These are of great strength and size, and there are some accessory muscles to the thigh and leg. The long spine of the back has powerful processes, and the jar of the great jumps is received by two vertebræ which, anchylosed or united together, form the sacrum. The tail is made up of many vertebræ, and covered with muscles. The great blood-vessels running underneath it have many chevron, or V-shaped, bones, to protect them from pressure. The marsupial bones, one on each side, are long, and broad below; they are movable on the pubis, and afford attachment to muscular fibres, act as a pulley for others, and strengthen the walls of the abdomen. Formed within muscles and tendons, they are rather bony growths than parts of the true skeleton, and hence they may be absent in some of the order, although they are always present in the Kangaroos.

Although well provided with strong limbs and muscles, and acute senses, the Kangaroos living the life of the deer and cattle of other regions than Australia, are subject to the attacks of beasts of prey and hunters. In Australia the great Carnivora do not exist, but there is a native dog, the Dingo, aborigines, and trained dogs and colonists, who enjoy a Kangaroo hunt. The native dogs stalk and run them down, the natives spear them after sometimes forming a great circle and closing in and yelling and shouting. But the rifle and trained hounds have dislodged many more than the natives, and the animals are becoming scarcer near the settlements than in former years. Dogs which run by sight afford many an exciting hunt, and the Kangaroo starts off, bounding at a great rate, and clearing all sorts of impediments with ease. It is hard riding to keep up with the chase, and especially in hot weather, when the Kangaroo often escapes, thanks to its greater powers of endurance. Sometimes the Kangaroo will stand at bay, and will rip up a solitary Dog with its claws, or will kill with a single blow of the leg and tail. Three or more Dogs are usually laid on, one more fleet than the others, to “pull” the Kangaroo, while the others rush in and kill it. Mr. Gould[88] says that it sometimes adopts a singular mode of defending itself, by clasping its short, powerful fore limbs round its antagonist, leaping away with it to the nearest water hole, and then keeping it beneath the water until drowned.

Mr. R. Foulerton, who has paid some attention to the habits of the Marsupials, writes that the Great Kangaroo, although its numbers have been greatly diminished in some pastoral districts, still is numerous enough to render some runs almost worthless for pastoral purposes. They may be seen there in thousands, eating off all the best grass, and in the bad seasons reducing the cattle to starving point. They have few enemies but man, as even the native Dog will never attack them, unless they are very young. An “old man” Kangaroo is a formidable opponent; he will severely wound and even kill a man, unless approached cautiously. Their mode of attack is to “hug” him bear fashion, and then rip him with the hind foot. When pursued, they generally take to the water, and there stand at bay, and the luckless man or dog who gets within their grasp is forced under the water, and held there until drowned. The middle-aged Kangaroos, or Flyers, easily outstrip the hunting Dogs at the start, but they are gradually gained upon. When caught, the Kangaroo fights to the last.

The diminutive fore limbs are separated by narrow shoulders, and although the upper arm is short and well furnished with muscles, the fore arm is long, slender, but very movable. The hand is short and broad, and there are four curved, sharp claws, the first one, or thumb, being the smallest, and the third and fourth the largest. The hair covers over the fingers to the claws, which can separate widely, grasp and hold, and be bent on the palm. The movements of the wrists and fore arms are considerable, and a large and long upward-turning muscle is in the space between the ulna and radius (the bones of the arm). Moreover, the ulna joints with a cavity in the cuneiform bone of the wrist; and the first row of wrist bones has three in it, and the second has four. The first phalanges, or those of the thumb, are not placed as a thumb in relation to the wrist bones, and it is the outer fingers that grasp with their claws. As the Kangaroo has to lift up its arm, there is a collar-bone, and the arm bone (humerus) is perforated on the inner side of the end above the elbow; and the olecranon is long.

The bladebone has a curved ridge, and the muscles of the upper part are less than those which are attached to the part below it. There are thirteen pairs of ribs to the chest.

The skull is long and comparatively smooth, and even the ridges for the temporal muscles are only slightly raised; and in old Kangaroos the bones do not unite or anchylose as they do in the other Mammalia hitherto noticed. The teeth are not used as weapons of offence, but simply to graze with, and the lower jaw is not quite solid at the chin, but only so below, so that the lower incisors can be slightly separated. The ear-bone is remarkable for being separated into three parts, namely, the temporal or squamous, the petrosal, and the tympanic; and this is rather a reptilian character. Moreover, the air-chambers of the side of the under part of the skull are in the form of rounded prominences, or “bullæ.” They are situated in the lower part of the ear-bone, called squamosal. The zygoma, or process between the cheek (malar) bone and the ear, is hollow, complete, and arched, its front part being, moreover, extended downwards in a projection which reaches below the grinding teeth, and resembles that of the Sloths somewhat. The lower jaw has its back part, or angle, bent inwards (or inflected) strongly, and this is, except in one set, a characteristic of the Marsupiata.

The Kangaroo, being a vegetable feeder, has a stomach suited for the diet, which also permits of a certain amount of regurgitation of food up again into the mouth, when a kind of chewing of the cud occasionally is indulged in. The stomach is large and long, resembling the colon or large intestine of the highest Mammalia in its general shape. It measured, in one instance, according to Owen, no less than three feet six inches, the measurement following its bends or curvatures. It consists of a left, middle, and right or pyloric division. The left ends in two round sacs, and these are really continuations of the stomach separated to a certain extent by a peculiar arrangement of the three bands of muscular fibres which pass separately along the organ. Numerous clusters of secreting glands are found in the mucous membrane of the stomach in its middle part, and they disappear near the pylorus where the tissues are thick and corrugated. The animal has a small intestine, a cæcum, and a large gut, but this last is not much larger than the first part of the stomach. The organs of the circulation of the blood resemble those of the other Mammalia, but there is a distinction which relates to the short period during which the young Kangaroo is a portion of the maternal being. So soon is it born, and so soon therefore must it breathe, that before the heart has grown much, it has the blood from the lungs and the rest of the body running through it. The young Kangaroo breathes when its heart is not fully developed, yet it has the perfect double circulation set up. The auricles of the heart communicate as in other Mammals until birth, but the duration of this communication is very short in the Marsupial, and its traces so evident in the other Mammals are wanting in it. The arteries of the body are simpler than in those Mammals which have a more complicated intestinal arrangement, and Owen, in his great work on the Marsupials, has pointed out that the hind limbs and tail are supplied with arterial blood by vessels which have an arrangement not without its similarity to that of birds. Leading a very simple life, and one of great sameness, moving in a manner which does not require much complexity of muscular action, the nervous system of the Kangaroo could not be expected to be highly organised or fully developed. The brain is small for the body of the animal. It is simple in form, and does not cover the cerebellum, which is visible behind, and has a little lobe on each side. The surface of the brain proper has a few convolutions on it, and more perhaps than the Rodent Mammalia have. The commissures of the brain, which relate to the complexity of the method of life, are unequally developed. The central one, or the corpus callosum, is small, and the front one is very large. Finally, the part of the brain which refers to the sense of smell is large, but hidden by the brain proper, and its nerves supply a large surface in the nose, at its upper part at the base of its skull.

The young Kangaroo, when very small, and almost transparent, comes down from the womb into a canal, and gets into the uro-genital sac, as it is termed. Thence it is taken by the mother, and put into the marsupium, or pouch, where it fixes on to a nipple, and holds on. As the little one is ever “at the breast,” it might have any quantity of milk go the wrong way, but this is provided for by the upper part of the organ of voice (the larynx) being prolonged at the back of the nose, above the level of the long nipple. Breathing goes on through the nose, and swallowing safely through the gullet.

THE HARE KANGAROO.[89]--THE TURATT.

There are many kinds of Kangaroos, and one of them, which is solitary and nocturnal in its habits, is called the Hare Kangaroo, of which Mr. Gould writes:--“The name of Hare Kangaroo has been given to this species as much from its similarity of form and size to the common Hare as from its similarity of habits. I usually found it solitary, and sitting alone on a well-formed seat under the stalk of a tuft of grass on the open plains. For a short distance, its fleetness is beyond that of all others of its group that I have had an opportunity of coursing. Its powers of leaping are also equally extraordinary. While out on the plains in South Australia, I started a Hare Kangaroo before two fleet Dogs. After running to the distance of a quarter of a mile, it suddenly doubled and came back to me, the Dogs following close to its heels. I stood perfectly still, and the animal had arrived within twenty feet before it observed me, when, to my astonishment, instead of branching off to the right or to the left, it bounded clear over my head, and, on descending to the ground, I was able to make a successful shot, by which it was procured. It has the end of the nose covered with a fine set of hairs. The fur is long and soft and very hare-like, and it has small limbs and sharply-pointed nails.”

THE GREAT ROCK KANGAROO.

This is very different from its timid congener just described. It inhabits the sterile and rocky mountains in the south-eastern part of Australia. It scampers about the rocks, and readily escapes Dogs, and it is a dangerous and formidable animal to approach, for it will, if closely pressed, turn on its enemy, and force him over the rocks. It bites, and uses its strong fore-arms very efficiently. It is called Macropus robustus, and is often found in companies of four or six; and it has more powerful fore-limbs than the Great Kangaroo, which is even sometimes the smaller of the two. It has the part of the nose called the muffle without hair.

THE RED KANGAROO[90] is so called from the red tint of the male, which is sometimes marked under the neck and elsewhere. It was found in the plains near the Darling and Murrumbidgee rivers, and is celebrated for its great fleetness; and the female is often called the “Flying Doe.” It is as fast as the Agile Kangaroo,[91] which is long-haired, and is found in Northern and Eastern Australia.

Van Diemen’s Land has a Kangaroo with a long, deep-grey fur, with red on the back of the ears, neck, and shoulders; and it is called the Brush Kangaroo by the settlers. It is eaten and highly esteemed, and its skin is exported for leather. Liking the dense and damp forests of the island, it finds a safe retreat therein, and probably this is what keeps them from extinction, for they have been killed by the thousand, in order to supply contracts for boot-leather. The young of this Kangaroo, which is also called after Bennett the naturalist (Macropus Bennetti), does not leave the pouch of its mother permanently, until it is as large as a Rabbit.

In the north of Australia, in the region of King George’s Sound, there is a small Kangaroo which is not larger than a common Rabbit, and it is a very interesting example of how species may differ from the type of a genus. It has a slender and rather short tail, which is rather scaly, and has but a few hairs on it, but it is not very short. The ears are short and round, and the hind feet are short. The departure from the configuration of the Great and Brush Kangaroo shape is therefore great. It is called the Short-tailed Kangaroo. The last four kinds mentioned are grouped together with others under a sub-genus, Halmaturus (ἅλμα, a leap, and οὐρά, a tail).

THE BRUSH-TAILED ROCK KANGAROO.

Almost as strange as the slender-tailed Kangaroo are those which are called the “brush-tailed,” and which inhabit rocky situations (Macropus penicillatus). Mr. Waterhouse thus notices them:--

“Whilst the Kangaroos of the plain have the fore part of the body slender and light, great strength in the hinder parts, combined with a long leg and foot, adapting them to fleetness, the tail powerful, and assisting in the support of the long body, we perceive certain modifications in the form and structure of these parts in the Rock Kangaroos which adapt them to their particular habitats. The body, more compact in form, requires but little assistance from the tail for its support, the leverage being less; and the feet are, though powerful, comparatively short, and remarkably rough beneath, being thickly covered over this part with hard tubercles, which no doubt prevent the foot from slipping. The nails of the two larger toes are shorter than usual, and, indeed, in some of the species, scarcely project beyond the fleshy pads with which the toes are terminated, and on the upper surface of which the nails are placed. A long and slender foot, with long nails, as in the typical Kangaroos, it is obvious, would be ill-adapted to an animal which has to leap to and balance itself upon the small ledges of the rocks. The tail is large, but not thickened at the root, as in the plain Kangaroos; and, unlike the tail in those animals, it is clothed with long hairs, which, gradually increasing in length from the base of the tail, become very long and bushy at the opposite extremity. It serves to steady the animal in its leaps, and to balance the body when perched in situations which require it, but is of little assistance in supporting the weight of the trunk. Its muffle, that is to say, the end of the nose, is naked, as in the scrub-inhabiting Kangaroos just noticed, and it forms the type of the sub-genus Heteropus” (ἕτερος, altered, πούς, foot).

One of these was hunted and shot amongst the woods of Liverpool plains, New South Wales, by Sir Edward Parry, who wrote that they appear to be gregarious, and seem to prefer the neighbourhood of rocky ground, in which they had holes, and to which, when hunted, they retreated. They swarm along in groups one after the other, and jump from side to side, alighting on ledges so slightly prominent that their resting thereon appears to be an impossibility. They go into caves and holes in the rocks during the day, and they enjoy the night, and gambol and feed by moonlight.

A Rock Kangaroo, with white and black bands on it, inhabits Western Australia, and a short-eared kind enjoys the hot sands and high rocks of Hanover Bay. There is a Kangaroo in the island of New Guinea (Macropus Brunii), and it was the first seen by Europeans.

THE COMMON TREE KANGAROO.[92]

This is an inhabitant of New Guinea, and instead of frequenting the brush and scrub, which are not physical features found in the island, or the rocks, it lives in the forests, and is no mean but rather a good climber of trees. There is a Kangaroo look about the animal, even when it is seated on a thick branch, but the fur is very different to that of its fellows of Australia. The fur looks coarse and harsh, and is not very unlike that of a Bear. There is no soft under fur, but all the hairs are long and resemble the long ones of the Kangaroos, and the ears are quite clothed with it. Then, as the animal glides down the stem of a tree, the shortness of the hind legs becomes apparent; moreover, the claws on the foot do not resemble those of the Kangaroo. The feet are stout but rather short, and the toes are more equal in size than in the other Kangaroos. The claw of the outer toe is often on a line with the middle of the longest one (the fourth), whilst the nails of the double inner toe extend slightly beyond its base. The nail of this large fourth toe is about an inch in length. Then the fore limbs are nearly as large as the hind ones, and are very strongly made, and so are the hands, the claw of the middle finger being three-quarters of an inch in length. It has a clumsy-looking head, with a high muzzle and small lower jaw. The upper lip is straight. It has a large face and small ears, and the colour of the fur is brown-black and yellow-brown. The tail is very long, tapers slightly, and is considerably of use in steadying the climber, and it is carried very much after the fashion of the other Kangaroos when the animal has come down from its tree and hops off to its retreat. A specimen in the Zoological Gardens of London had grizzled-grey fur, whiter underneath the jaws and on the neck and limbs, and the ears were wide apart, and the powerful fore limbs ended in five claws. The tail tapered but very little. This was probably a second species called the Brown Tree Kangaroo (Dendrolagus inustus).

These Tree Kangaroos have a small superior canine tooth on each side, and the hinder incisor is not grooved. Hence they form a sub-genus, which is called Dendrolagus (δένδρον, a tree, λαγός, a hare), Tree Hare.

THE KANGAROO-RATS.[93]

These are also called Potoroos, and are of small size, being about that of a Hare or Rabbit. They have a compact body, the neck being short, and the ears are rather rounded, so that their shape is unlike that of the Great Kangaroo, but it resembles that of the smaller kinds somewhat. They have a rat-like shape, both hind feet like the Kangaroos, a long tail, and peculiar teeth. The head is very like that of a Rodent, and the incisor teeth in the upper jaw have the front ones the longest. The canine teeth exist in the upper jaw, and the premolar is large, and has numerous distinct vertical grooves on the outer and inner sides; and the front molars are the largest, the smallest being in the rear. The toes of the fore foot are unevenly developed; the three central ones are large, and those at the side are small. The nails are solid, broadest above, and much compressed. The foot is long, and the fourth toe and nail are greatly developed. The fifth toe is next in size, and the small second and third are coupled together by skin, and form a projection, with two small nails, which are useful in combing and scratching the fur. The first toe is absent. The Rufous Kangaroo-Rat inhabits New South Wales, and is very common.[94] Its nest is made up of grasses, and is frequently placed under the shelter of a fallen tree, or at the foot of some low shrub. During the day the little animal lies curled up in its nest, but it occasionally reposes in a “seat” like the Hare Kangaroo; but it never sits in the open plains. On being pursued it jumps like a Jerboa, with great swiftness for a short distance, and seeks shelter in hollow logs and holes. Its food consists of roots and grasses. Another is a native of Van Diemen’s Land, and keeps to the open, sandy, or stony forest land, rather than to the thick and humid bushes. It is called Hypsiprymnus cuniculus.

None of the animals hitherto described as Kangaroos have any prehensile power in the tail; but in one group of the Kangaroo-Rats, the tip of the tail has a brush of long hairs above, and is clothed beneath with short hairs, which are closely applied to the skin. This structure, and the motion of the muscles beneath, give the Tufted-tailed Kangaroo-Rat[95] of New South Wales a power of encircling and holding objects, especially for seizing grasses with which to make its nest. This is placed in a hollow in the ground, excavated for its reception, and its opening being on a level with the surrounding herbage, the practised eye of the native is required to discern it. After the little things creep in, they drag some grass after them, and close up the place. In the evening, they sally forth and scratch and dig up roots with their strong fore-claws.

THE RAT-TAILED HYPSIPRYMNUS.[96]

The Rat-tailed Kangaroo-Rat is about fifteen inches and a half long, and the tail measures, in addition, more than nine inches. It has a long head and rather short hind feet, and the rat-like tail has short stiff hairs on it which do not quite hide the scaly skin beneath. The body fur is long and loose, and dusky brown, more or less tinted with black and pale yellowish-brown. The end of the nose or muzzle is spotted, and the ears are short and rounded. This little animal lives in New South Wales, and was that which was first described by Hunter under the name of Potoroo, or Poto Roo, being the “Bettong” of the natives of New South Wales. The stomach of the Kangaroo-Rats is less sacculated than that of the Kangaroos, but its left-hand portion is enormously developed in proportion to the rest, and may be compared with that of the Ruminantia in point of relative size. It may be noticed that the lower jaws of the Potoroos, which are largely inflected at the angle, articulate with the skull rather differently to those of the Kangaroos. In these last, the cavity at the base of the zygomatic process which receives the lower jaw is broad and slightly convex, permitting considerable side-to-side movement which is useful in the occasional “cud chewing.” But in the others the cavity barely deserves the name, it being a nearly flat surface, and, therefore, not much motion, except that of an up-and-down kind, is possible to the jaw. The organ of hearing has been slightly noticed in the Great Kangaroo in a former page, and it is necessary to observe that the tympanic bone does not form a perfect tube in the Potoroos as in the Kangaroos, and that the surface of the auditory cavity is also increased by a “bulla,” or bony cavity, bulging out at the under part of the skull. Corresponding “bullæ” were noticed in the Rodentia, but in their case the swelling is in the temporal bone, whilst in the Marsupials, with the exception of the Wombat, they are formed out of the sphenoid bone (the great ala). Moreover, the Potoroos, like the Kangaroos, and some of the other Marsupials (the Phalangers and Koalas), have the ear chamber prolonged, by a number of cells, into the zygomatic process of the temporal bone. The Kangaroo-Rats are numerous, and there are many species. They are distributed in New South Wales, Western Australia, Van Diemen’s Land, and South Australia, and to the north-east.

Sir R. Owen investigated the anatomy of a small Kangaroo-Rat which had been described by Mr. Ramsay in Australia, and which was remarkable for its musky smell. It is a long and slender-bodied little animal, measuring about one foot three inches and a half from the snout to the end of the tail, which is five inches and nine lines in the female, and rather less in the male. Its hinder legs are shorter, and the head is more slender and pointed than in the Kangaroo-Rats just described. The fur is of moderate length, pretty closely applied, and has numerous rather long hairs scattered here and there, the visible portions being black or blackish, or pointed. These are relieved by the dark and light-barred colour of the visible part of the shorter hairs, all the hairs being of a leaden-greyish tint at the skin. The upper surface of the body has a close and stiff fur of rich golden colour, mixed with black; the head, face, and lower parts of the legs are dark brownish-grey; and there are a few patches of white along the centre of the throat and chest. The fur covers the tail for half an inch or more, and then the rest is naked, and covered with a network of scales about three to a line in length. The scales are black above, and a few minute and very short hairs project from the interstices of the scales. The animal has a naked muffle and rounded ears. The hind foot is remarkable, for whilst the skull and dentition of the creature would associate it more with the Kangaroo-Rats, the position of the first toe (wanting in the Kangaroo-Rats) resembles somewhat that of the Phalangista group, or the Phalangers, which will be noticed further on. The sole of the foot is long, and there is a nailless projecting first toe, like a thumb; next come the second and third toes--small, united by skin, and leaving the two combing-nails visible; and then the largest, or fourth toe, is followed by a smaller fifth. Sir R. Owen judged that this animal was an occasional climber of trees, but that its usual locality was on the ground. Mr. Ramsay states that it lives in the Rockingham Bay district, and that it frequents the dense and damp positions of the scrubs which fringe the rivers and clothe the sides of the coast range. Its habits are diurnal, and its movements are graceful. It procures its food by turning over the rubbish in search of insects, worms, and tuberous roots, frequently eating the palm-berries, which it holds with its fore paws, after the manner of the Phalangers, sitting up on its haunches, or sometimes digging. They have a pouch, and two young ones have been found in it. Considering the importance of the great toe to the animal, and its linking together the climbing and jumping Marsupials, Sir R. Owen acknowledged the necessity of recognising Mr. Ramsay’s name of Hypsiprymnodon moschatus, and of thus bringing in a new genus into a new family in the Kangaroo series with two large front teeth in the lower jaw.[97]

II.--THE WOMBAT FAMILY.--THE PHASCOLOMYIDÆ.

THE WOMBAT.[98]

On looking at a picture of a Wombat, the outside distinctions between it and all the Kangaroo family may be seen at a glance, and an examination of its anatomy affords still greater evidence of differences which, to a certain extent, relate to the fact that the animal now under consideration is a burrower and gnawer. About two to three feet in length, the Wombat has only a small stump of a tail, a low body, small feet, and strong limbs, ending in broad extremities, well provided with claws. It has moderately long and coarse fur of a grey-brown colour, and there is some white about the short ears, and the feet are black. It is usually a plump animal, with a bare black muzzle, and feet naked beneath, and covered with little tubercles of flesh. The claws are large, and those of the fore feet (five in number) are solid and but little curved, whilst the four on the hind feet are curved and concave beneath. It has long moustache hairs, and plenty of them. Sir Everard Home had one, and he found that its principal desire was to get into the ground, and to do this it worked with great skill and rapidity, covering itself with earth with surprising quickness. It was very quiet during the day, but was in constant motion during the night; was very sensible of cold; ate all vegetables, and was particularly fond of new hay, which it ate stalk by stalk, taking it into its mouth like a Bear, in small bits at a time. It was not wanting in intelligence, and appeared attached to those to whom it was accustomed, and who were kind to it. When it saw them, it would put up its fore-paws on their knees, and when taken up would sleep on the lap. It allowed children to pull and carry it about, and when it bit them it did not appear to do so in anger or with violence. When wild, the Wombat hides up during the day, and quits its retreat at night, to dig and get grass and roots. It is by no means an active animal, and shuffles along like a Bear. The Wombat has a slit-like, imperfect marsupium, and the special peculiarities of its order, such as marsupial bones, the inflected lower jaw, and double uterus. On the hind foot the innermost or first toe is very small, nailless, and placed at right angles to the foot, and the second, third, and fourth toes are joined by skin, and have larger claws than the small fifth toe. The stomach is simple, and has a peculiar glandular apparatus, and the cæcum is short, and has an appendage as in man and some monkeys. The teeth are remarkable for their number in relation to those of the Kangaroos, and for having no rootlets. The incisor teeth greatly resemble those of a Rodent, like the Rat. They are two in number in each jaw, and are widely separated from the other teeth. The molars are long, curved, and, like the incisors, have no true fangs, but persistent pulps. They are divided into two nearly equal parts by a fold of the enamel entering deeply into the body of the tooth on one side, and a slight indentation on the opposite side.

The number of the persistent teeth is as follows:--Incisors, 2/2; true molars, (4-4)/(4-4). It is the only Marsupial which has an equal number of incisors in both jaws. There are no canines. As the Wombat uses much force in gnawing, the muscles of the jaws and their bony attachments are large; consequently the temporal ridges are strongly marked. There is a deep and strong zygomatic arch, and in the lower jaw the turned-in angle is of great size. The chin is also large, and the joint of the jaw also. The sutures of the bones of the skull are scarcely ever obliterated, and the auditory “bullæ” are formed in the temporal bone. With regard to the marsupial bones, they are long, flat, curved, and, moreover, less expanded near their attachment to the pubis. The ribs are fifteen in number on each side, and the collar-bones are large and stout. There is a curious power of movement of the ankle, so that the foot can imitate the turning movements of the wrist and fore-arm of man. This pronation and supination is because the small bone of the leg, the fibula, is free and not attached to the other bone (tibia), and because there is a muscle whose action is to move the fibula after the fashion of the corresponding muscle in the fore limb. The stomach is smaller than in the Kangaroos, and has a large gland.

The Wombat has been found in South Australia, Van Diemen’s Land, Bass Strait, and in New South Wales.

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II. THE PHALANGER, POUCHED BADGER, AND DASYURE FAMILIES

THE PHALANGER FAMILY--THE KOALA--Habits--Characteristics--THE CUSCUS--THE VULPINE PHALANGER--THE DORMOUSE PHALANGER--Habits--Remarkable Characters--THE FLYING PHALANGERS--Its Flying Machine--Habits--THE SQUIRREL FLYING PHALANGERS--Habits--The Parachute-like Membrane--Exciting Scene on board a Vessel--Characteristics--THE OPOSSUM MOUSE--THE NOOLBENGER, OR TAIT--A Curiosity among Marsupials--Distinctive Features--THE POUCHED BADGER FAMILY--Characteristics--THE RABBIT-EARED PERAMELES--THE BANDICOOT--THE BANDED PERAMELES--THE PIG-FOOTED PERAMELES--Discussion regarding it--Characteristics--THE DASYURUS FAMILY--Characteristics--THE POUCHED ANT-EATERS--THE BANDED MYRMECOBIUS--Description--Great number of Teeth--History--Food--Habits--Range--THE URSINE DASYURE--Appearance--“Native Devil”--Ferocity--Havoc among the Sheep of the Settlers--Trap to Catch them--Its Teeth--A True Marsupial, though strikingly like the Carnivora--Skeletal Characters peculiar to itself--MAUGE’S DASYURE--THE DOG-HEADED THYLACINUS--Description--Resemblance to the Dog--Habits--Peculiarities--THE BRUSH-TAILED PHASCOGALE--Description--Other Varieties.

III.--THE PHALANGER FAMILY.--THE PHALANGISTIDÆ.

The loftiest of the gum-trees of the country from Moreton Bay to Port Phillip, and even more widely than this, were often the familiar haunt of a small Marsupial animal, not unlike a little Bear, about two feet in length, and without a tail. It is a famous tree-climber, and its stout body, small head, short limbs, and well-developed feet, are all cased in an ash-grey fur. It has moderate-sized ears, which are hidden by the long hair of the head, and it has a short and nearly naked black muzzle. The eye is large and without eyelashes. The natives climb up the trees after it, according to Mr. Gould, with as much ease and expertness as an European would get up a long ladder, and having reached the branch, perhaps forty or fifty feet from the ground, they follow the animal to the extremity of a bough, and either kill it or take it alive. This animal is called the KOALA, and it feeds on the tender shoots of the blue gum in preference to those of any others, and it rests and feeds in the boughs. At night it descends and prowls about, scratching up the ground in search of some peculiar roots, and it seems to creep rather than to walk. When angry it utters a long, shrill yell, and assumes a fierce and menacing look. They are found in pairs, and the young soon learn to perch on the mother’s shoulders. Mr. Gould says that, unlike most quadrupeds, the Koala does not flee upon the approach of man, and that it is very tenacious of life. Even when severely wounded it will not quit its hold of the branch upon which it may be. The animal has a nice thick fur, which nearly hides the ears, and the pouch is large. A careful examination of the animal shows that it differs from the Kangaroos and Wombats; it is more like the latter than the former, but it is sufficiently distinct to be placed in another family, the Phalangers, in which the incisors are six above and two below, and there are two canines in the upper jaw, and in some, two in the lower jaw, but not in all. There are two premolars above and below, and either six or eight molars in the upper and lower jaws. The head is rather small, and the face is short, the upper lip being cleft. The limbs are equal; the fore feet have five well-made toes with compressed and curved claws; the hind feet have five toes, of which the first or inner one is large, nailless, and at right angles to the rest, and opposable to them. The second and third toes are shorter than the others, and are united in a common skin, and they have nails. The fourth and fifth toes are curved and have compressed claws. The name Phalangista is derived from this union by skin of the phalanges of the foot. The tail may be absent, or long, and more or less prehensile, but sometimes not.

There is a well-developed pouch, and the stomach is simple, and the cæcum is usually very long and large. One young one is produced at a birth.

The Koala, or Native Bear,[99] may be taken as the type of the tailless group, and it belongs to the genus Phascolarctus.

The CUSCUS, or Ursine Phalanger,[100] belongs to a second division, for it has a prehensile tail. They are common animals in the dense woods of the Island of Celebes. They squat on the branches half asleep by day, but are lively enough at night, and it is said that they have a fancy for flesh as well as fruit. A pretty spotted Cuscus inhabits the islands of Amboyna, Waigeoe, Banda, and New Guinea, as well as Cape York.[101] They are dull in captivity, but when placed together they fight with fury, growling like Cats, and biting. They have small red eyes with a vertical pupil, short ears, and a very stupid look. They are all nocturnal in their habits, and feed on fruit, buds, leaves, meat, and eggs.

One of the Phalangers, called Cuscus albus, is abundant in New Ireland, Amboyna, Banda, and Timor, and is remarkable for its peculiar odour. The male is white, and the female reddish-brown in colour, both being about the size of a common Rabbit. It is slow in its movements, lives in trees, and takes good care to conceal itself, but its scent discovers it. The naturalists Lesson and Garnet stated that when they traversed the forests of the island the odour of the Cuscus was distinctly perceptible. It is stated that if these animals see any one, they suspend themselves at once by the tail, and if they are looked at steadfastly, they will drop by-and-by from fatigue, and are then easily caught; in fact, they pretend to be dead.

THE VULPINE PHALANGER.[102]--THE BRUSH-TAILED “OPOSSUM.”

Waterhouse describes this Marsupial to be about the size of a Cat, but in shape it is somewhat between a Squirrel and a Marten. It has long and somewhat pointed ears; and the tail, clothed with bushy, harsh, black fur, except beneath, near the end, where it is naked, is about as long as the body. The limbs are rather short, the muzzle is moderately long and foxy-looking, and the whole body and head, except the naked muzzle, are covered with a grey and black fur. The moustaches are long, numerous, and black, and the feet are yellowish-white, and the naked soles are flesh-coloured, the nails being dusky. The pupil of the eye is round and intensely dark in colour. They sleep during the day, and become active during the evening, and on the alert for their food, which consists, in the Zoological Gardens, of bread and milk, fruit and vegetables. They hold up the solid food between the hands as a Squirrel holds a nut, and nibble very much in the same manner. Their native haunts are New South Wales, Western Australia, and North Australia. They inhabit the large trees, usually the Eucalypti, selecting such as have the heart of the branches or trunk decayed, and they take refuge there during the daylight. At night they leave their nests and climb the branches of the trees which yield them buds and fruit. They descend to the ground for food, and doubtless now and then eat snails and small birds. When climbing they use the tail to hold by, and carefully grasp every support with it before they let go with their feet or hands. A brown-black species, closely allied, lives in Van Diemen’s Land.[103]

THE DORMOUSE PHALANGER.[104]

This is a very small Marsupial animal, about six inches in length, including the tail, which measures nearly, if not quite, one-half. It is like a little Dormouse, with its soft fur, ashy-grey in colour, large ears, and thick tail. They are broader, not so long in the leg, and usually larger than the Dormouse, and the eyes are larger, and the upper jaw overhangs the lower. But they look just as fat and sleepy in the daytime. The habits of these animals, moreover, are much the same, for the Phalangista living in Van Diemen’s Land feeds on nuts and other similar food, which they hold in their fore paws, using them as hands. They are nocturnal, remaining asleep during the whole day, or, if disturbed, are not easily roused into a state of activity. They come forth in the evening, and are then more easy and rapid in their movements. Some of these were kept in the Zoological Gardens of London, and it was noticed that they made great use of their tail, which is prehensile, and thus not like that of the Dormouse. They ran about a small tree, using their paws and tail to hang on by, and using the tail as a suspender when they descended. Sometimes the tail is thrown in a reverse direction, and is turned over the back, and at other times, when the weather is cold, it is rolled closely up towards the under part, and coiled up almost between the thighs. They are like little balls of fur, and are very gentle and harmless.

Mr. Gould states that another kind of these Dormouse-looking creatures is very abundant in the northern portion of Van Diemen’s Land, and that of all trees it appears to prefer the Banksia, whose numerous blossoms supply it with a never-ceasing store of food, both of insects and sweets. It undergoes a kind of hibernation somewhat similar to but not to the extent of that of the Dormouse.

These pretty little marsupials are remarkable by having only three true molar teeth in each jaw on both sides; but they have the usual two narrow, long, and pointed incisors in the lower jaw. The auditory bullæ on the base of the skull are large, and the hard palate has four openings in it. The lower jaw is slender behind, and the angular process is inflected, the process of bone being, however, slender and pointed. Their mouse-like shape is evident, but they have a large eye, and the ears are often more or less crumpled and pendent, but they start up and are erect at the least noise. There are three species of these Phalangistidæ, and they are included in a sub-genus, Dromicia. They live in Van Diemen’s Land, Western Australia, and South Australia. Some which were found in King George’s Sound district live in retreats under the dead bark of trees, and in holes in trees which have been burnt out.

THE FLYING PHALANGERS.

The next genus of the family Phalangistidæ contains the Flying Phalangers, which form the genus Petaurus. They have all the peculiarities of the Phalangers, and also a skin on the flank of the body, which is extended between the fore and hind legs, which serves to sustain the animal in the air, when descending from a height. They have a long hairy tail. The Yellow-bellied Flying Phalanger (Petaurus australis, Shaw) may be taken as the type of the genus, and is fourteen inches long in the body, and nineteen in the tail. The peculiar fold of fur, which is its flying machine, is attached to the fore leg as far as the elbow, and all down the legs to the great toe. It is common in all the brushes of New South Wales, particularly those along the coast from Port Philip to Moreton Bay. Mr. Gould states, in addition to this, “In these vast forests, trees of one kind or other are perpetually flowering, and thus offer a never-failing supply of blossoms, upon which the animal feeds. The flowers of the gum-trees, some of which are of great magnitude, are the principal favourites, and, like the rest of the genus, it is nocturnal in its habits, dwelling in holes of trees and in the hollows of branches during the day, and displaying the greatest activity at night, while running over the small leafy branches, sometimes even to their very extremities, in search of insects and the honey of the newly-opened blossoms. Its structure being ill-adapted for terrestrial habits, it seldom descends to the ground, except for the purpose of passing to a tree too distant to be attained by springing from the one it wishes to leave. The tops of the trees are traversed at a pace and with as much ease as if it were on the ground. If chased, it ascends to the highest branches, and performs enormous leaps, sweeping from tree to tree with wonderful address.”

A slight elevation gives its body an impetus, which, with the expansion of its membrane, enables it to pass to a considerable distance, always ascending a little at the extremity of the leap. By this ascent the animal is prevented from receiving the shock which it would otherwise sustain.

THE SQUIRREL FLYING PHALANGER.[105]

This little creature, called the Sugar Squirrel by the colonists, is very generally dispersed over the whole of New South Wales, where, in common with other Phalangers, it inhabits the magnificent gum-trees. Mr. Gould states that it is nocturnal in its habits, and that it conceals itself during the day in the hollows of trees, where it early falls a prey to the natives, who capture it both for the sake of its flesh and skin, which latter, in some parts of the colony, they dispose of to the colonists, who occasionally apply it to the same purposes as those to which the fur of the Chinchilla and other animals is applied in Europe. At night it becomes extremely active in its motions. It prefers those forests which adorn the more open and grassy portions of the country rather than the thick brush near the coast. By expanding the membrane attached to the sides of its body it has the power of performing enormous leaps. They have the power of changing their course to a certain extent when descending, parachute-like, from a height. It is stated that a ship sailing off the coast had a Squirrel Petaurus on board which was permitted to roam at large. On one occasion it reached the mast-head, and as the sailor who was sent to bring it down approached, it made a spring from aloft to avoid him. At this moment the ship gave a lurch, which, if the original direction of the little creature’s course had been continued, must have plunged it in the sea. All who witnessed the scene were in pain for its safety; but it suddenly appeared to check itself, and so to modify its career that it alighted safely on deck. This kind is not more than eight or nine inches in length, and its bushy tail is as long as the body. The soft fur of the tail, like that of the body, is a delicate ashy-grey. There is a long stripe of black fur from the naked tip of the nose to the root of the tail, and the cheeks are white with a black patch; the flank membrane is edged with white, and this is the colour of the underneath part of the body; the ears are long, and of a brownish flesh colour.

Another kind, with a yellow flank membrane, is short-headed, and it inhabits Port Essington, North Australia,[106] whilst the true Short-headed Flying Phalanger is found in New South Wales.[107] Probably it is the first of these which is found in New Guinea, and which has been called the Squirrel Flying Phalanger by mistake. These Flying Phalangers all have long and nearly naked ears, and the side membrane extends to the outer finger. They have the outer two fingers of the hand long and equal to each other, or very nearly so; the second and third fingers are distinctly shorter than these; and the inner finger is very short. Their dentition is--Incisors, (6/2); canines, (1-1)/(0-0); premolars, (3-3)/(4-4); true molars, (4-4)/(4-4) = 40. The incisors of the lower jaw are, as usual, long and pointed, and almost horizontal, whilst the upper incisors are large and dilated, so far as the anterior ones are concerned, and the next is smaller than the hindmost. The canine is large, and separated from the first premolar, which is large and compressed, and all the molars have rounded tubercles on them.

The OPOSSUM MOUSE[108] of the colonists of New South Wales used to be common in the neighbourhood of Port Jackson. It is about the size of a common Mouse, and of an ashy brown and grey colour on the upper parts and on the flank membrane; the rest is white. It belongs to the Flying Phalangers, but its side membrane scarcely extends to the wrist, and the thumb of the hind foot is large. It has only three true molars in each jaw on both sides, and the canine is close to the incisors. It forms part of the sub-genus Acrobata, whilst those already mentioned constitute the sub-genus Belideus (βέλος, a dart). Finally, the short-eared, white-bellied Taguan Phalanger of the scrub of New South Wales is the type of the sub-genus Petaurus.

GENUS TARSIPES.--THE NOOLBENGER, OR TAIT.[109]

This is an Australian curiosity amongst the Marsupials, and is a small, mouse-like thing, with a long muzzle, small ears, long tongue, and very few teeth. Its dental formula is--Incisors, (2-2)/(2); canines, (1-1)/(0-0); molars, (3-3)/(3-3). The fore and hind extremities have toes something like those of the Lemur, called Tarsius (Vol. I., page 248). The fore feet have five smallish toes, each thickened at the end, and a minute scale-like nail, which reaches neither the end nor sides of the toe. The hind feet have five toes on each, and the innermost has the formation of a thumb, and is slender and nailless. The second and third toes are very short, and are joined to the end and furnished with small pointed nails, which are directed upwards almost at right angles to the plane of the toe; and the fourth toe is twice as long as the second and third. The fifth is shorter than the fourth, and has a scale-like nail on the upper surface. This is the case with the fourth also. There is a long, slender tail. The small bones of this little honey-sucker are very thin, and the lower jaw has two slender and almost straight sides, and the inflection is wanting.

This little animal is rare, but it is to be found in West Australia, from Swan River to King George’s Sound. It is nocturnal in its habits, and catches flies in captivity with great ease. But its food is honey, which it gets like a moth, with its tongue. The tail is prehensile, and the little pouch contains four mammæ in the female.

The little Tarsipes, with its honey and insect diet, has a very long intestine and no cæcum, whilst the Koala has a cæcum more than three times the length of its body. The pigmy Acrobata has this organ disposed in a spiral curve in the left lumbar region. The marsupial bones are large in the Koala, and are long, broad, and flat, almost equalling the iliac bone in size. Finally, with regard to the parachute-fold of skin on the flanks of the Petaurists, it is a simple fold with very elastic tissues within, which draw it up to the body, more or less, when the animal is walking or standing. When, however, the limbs are extended after a jump, the membrane becomes very tense, and acts by increasing the surface of the body so as to oppose gravitation by the supporting power of the air.

IV.--FAMILY PERAMELIDÆ.--POUCHED BADGERS.

This group of Marsupials embraces two genera, Perameles and Chœropus, the first having several species and the last but one. They have all long, slender heads; large, long ears, with fleshy lobes; longer hind than fore limbs; the tail short in some, long in others, and hairy; and the pouch is directed backwards. They have a considerable number of teeth, there being ten incisors in the upper jaw and six in the lower; there are two canines in each jaw, three premolars in each jaw on either side, and four true molars behind them, making forty-eight teeth in all. The teeth have fangs, the premolars are compressed and pointed, and the molars have tubercles on them. The stomach is simple.

GENUS PERAMELES (BANDICOOTS).--THE RABBIT-EARED PERAMELES.[110]

The so-called native Rabbit of the Swan River district of Western Australia is abundant in the grassy country in the interior; and it frequents, in pairs, places where the soil will permit of burrowing. It is about the size of a common Rabbit, and has a long and pointed muzzle, which is naked at the tip. It has long, oval ears, which are tubular at the base. The eye is small, and the tail is a little shorter than the body. The legs are longish, and the fur is well grown.

This sharp-looking animal lives upon insects, and its favourite food is a large grub, probably the larvæ of a species of Buprestis beetle which infest the roots of the acacia trees. In order to obtain this peculiar food, it has to compete with the natives, who like it also, and often enough it has to rush to its long and deep burrows for safety. Its flesh is sweet, and is much sought after by the aborigines. One which was kept at the Zoological Gardens was very active in the evening, but usually slept during the day-time, when, sitting upon its haunches, with its head thrust between its hind legs, it appeared like a ball of fur. It was a very savage animal, and bit severely, holding on, moreover, if it could, with its teeth. It waddled on its hind legs alone, which were straddled, and the tail assisted in supporting the body. They have five toes to the fore-foot, of which the two outermost are rudimentary and nailless, the remaining three are well developed, and are furnished with strong solid nails, which cover the last phalanges which are cleft above in the longitudinal direction almost to the root. The hind feet have a rudimentary inner toe, the second and third are joined and are slender, and have two hollow nails, and the fourth is large and, like the fifth, which is well developed, has a solid nail sheathed on the end bone.

GUNN’S PERAMELES.--THE BANDICOOT.[111]

This is the animal which has given the native name to the genus, and Mr. Gunn, who discovered the species, informed Mr. Waterhouse that it is common in many parts of Van Diemen’s Land, going by the name of Bandicoot. It is a burrower, and lives principally upon roots, and it likes the bulbs which are introduced from the Cape and elsewhere into gardens. It is about sixteen inches long, and has a slender muzzle, moderate-sized ears, and the under parts of the body are white, the rest being grey and pencilled with black and yellow, except behind, where it is blacker. There are four broadish white bands on this part.

THE BANDED PERAMELES.[112]

This is a pretty little Perameles with a body about a foot in length, and a tail of about four inches long. It has rather a sharp and long snout, rather large ears, which are broad at the base, and long and pointed at the tip. The fur is longish and harsh, and is pencilled with black and yellow in about equal proportions on the upper part of the body, there being a black ground colour on the hinder part of the back. There, however, there are three broad yellow-white bands, the foremost of which crosses the back. The feet and under parts are white, and the tail is of the same colour underneath, but black on the top. The feet are slender, and the hind ones have a rudimentary inner toe, naked beneath, in front, and at the heel. In the skeleton this inner toe has one or two phalanges, and a small tubercle without a nail is visible before the flesh is removed. It inhabits Southern Australia from east to west. This kind resembles the Bandicoot of Van Diemen’s Land on the other side of Bass Strait, and may be considered its representative. It is smaller than the Van Diemen’s Land species, but its tail is longer; moreover, the ear exceeds those of the insular forms in size. Like the other Perameles, the pouch for the young opens backwards. “Though provided with strong claws it rarely burrows,” says Mr. Krefft, “and it is a great enemy to little Rodents. It tumbles the Mice about with its fore paws, breaks their hind legs, and eats the head.” New Guinea contains a short-legged Perameles,[113] which appears to be deficient in the usual number of upper incisor teeth; and another[114] resembling the common Bandicoot.

GENUS CHŒROPUS.--THE PIG-FOOTED PERAMELES.[115]

A very rare little, large-eared, small-legged animal was found by Sir Thomas Mitchell on the banks of the River Murray, and its appearance was so remarkable that much attention was paid to its anatomy, whilst unfortunately nothing particular was learned regarding its natural history and habits. Subsequently the little creature, whose body is about nine inches and a half long, the tail measuring in addition about four inches, was found in the interior of the country near the Swan River. It is an active little animal, and a hunter of insects, but it will feed upon vegetable substances also. Mr. Gould states that, like the Perameles, to which it is allied in many parts of its construction, it forms a nest composed of leaves and other substances. The pouch is deep and runs upwards, and not like that of the Kangaroo, and there are eight teats. At first there was much discussion whether the animal had a tail, but there is no doubt about its possessing one when in the perfect condition. The slender fore limbs, no thicker than goose-quills, end in two very small digits, and they are provided with small, compressed, and but little curved nails. They have a small fleshy pad on their under surface, behind which is a smaller one. The hind legs are longer than the front ones, and are almost as slender. The foot is long, and at first sight appears to have only one large toe, for the others are very small and far removed from the end of the foot. The outer little toe has a small nail, and the inner toes, joined, are almost as small, but they have hollow nails. The greatly-developed toe has a conical and compressed nail, but beneath there is a large fleshy pad; the rest of the foot is hairy. Hence it appears that the heel is not put to the ground. The colour of the long, loose, soft fur is brown-grey above, and yellowish-white beneath, the limbs and the fore feet have a whitish tint, and the large toe is of a dirty white colour. So far as the skull and teeth are concerned, the little Chœropus greatly resembles the other kinds of Marsupials which are classified under the genus Perameles. Sir Thomas Mitchell noticed the broad head and very slender snout, which, he stated, resembled the narrow neck of a wide bottle, in the specimen which the natives took from a hollow tree after chasing it on the ground. In the construction of the skull and in the number of the teeth, this long-eared creature resembles the rest of the genus Perameles. In the upper jaw there are five incisor teeth on each side, and they are close, and the canine is small, and resembles a premolar, and is slightly distant from the incisors. The first premolar is separated from the canine by a space of one line and a half, and slightly from the second premolar; and the second and third premolars and the four molars form a continuous line.

V.--THE DASYURUS FAMILY.--DASYURIDÆ.

These animals are all carnivorous, and prey upon small quadrupeds and the young of large ones, as well as upon birds and insects. They are of different shapes and sizes, according to the genera to which they may belong; and whilst some resemble the Shrew Mice somewhat in outward appearance, others are like the Marten, and one important group may be compared with Short-legged Wolves, or Jackals. Varying in size from that of a Mouse to a small Wolf, the members of the different genera of this family are equally variable in the number of the teeth, of the claws, and in the development of the marsupial pouch and its bones. They all have rather long muzzles and furry tails, which, however, are not prehensile. The second and third toes of the hind feet are disunited and well developed, and the thumb-toe is small or absent. There are eight incisors in the upper jaw, and six in the lower.

GENUS MYRMECOBIUS.--THE POUCHED ANT-EATERS.[116]

The BANDED MYRMECOBIUS may be taken as an example of this genus. It is about the size of a Rat, but it is more Squirrel-like in shape, and has a long and pointed muzzle. The tail is long and furry, with long hairs also; and the prevailing colour of the body is reddish, but posteriorly it becomes dark or black. There are nine bands of light or white colour on the sides of the body, from the back over the flanks, and the crupper is also marked with a band. The head is long, the ears are moderately long, narrow, and pointed, the gape is considerable, and the small pointed snout has some rather long smellers; there are also some long hairs under the eye. A black mark runs on the cheek to the ear, and has white hairs above and below it. The fur is somewhat remarkable. The under hair is scanty and whitish-grey, and the upper hair is rather coarse, short, and depressed on the fore parts of the body. It is long on the hind and under parts, and the hairs on the fore part of the back are black near the skin and reddish at the tip. The fur of the head is short and brownish above, being composed of a mixture of black, fulvous, and a few white hairs. The fore legs are rather stout and strongly made, and the five curved and compressed claws are admirably adapted for its method of life, which consists of insect-hunting by digging. The hind limbs are suited to support the weight of the animal, as it scratches with the fore feet, but they are deficient in the first toes. The whole animal is about seventeen inches long, seven inches being included in the tail. This animal has a greater number of teeth than any other Marsupial, and, indeed, they are only surpassed by some Cetacea and Edentate Ant-eaters amongst the other Mammalia. There are fifty-two teeth in the mouth--namely, eight upper and six lower incisors, four canines, six compressed false molars behind the canines above and below, and ten small true molars above, and twelve below. The canines of the lower jaw are incurved, and the last lower molars are worn in ridges internally. The number of teeth appears, however, to be variable, and some have fifty-four and others less than fifty.

The Myrmecobius, although it has the inflected condition of the lower jawbone and small marsupial bones, not more than half an inch in length, has no pouch. The young adhere to the mother’s nipples, and are protected by the comfortable fur and long hair of her body.

The Banded Myrmecobius was first discovered by Lieutenant Dale, who procured a specimen whilst on an exploring expedition into the interior of the Swan River Settlement, about ninety miles to the south-east of the mouth of the river. Two specimens of this very elegant little animal were seen by Lieutenant Dale, both of which fled to hollow trees for shelter upon being pursued. The district in which they were found abounded in decayed trees and ant-hills; and, from some peculiarities in the dentition of the animal, combined with its extremely long and slender tongue, it became evident that its food was insects, and the softer and smaller species, for procuring which, by scratching up the earth, the strong fore feet and claws appeared to be adapted. Indeed, the peculiarities of structure, combined with the fact that the animal was found in the vicinity of ant-hills, suggested that its food, in all probability, consisted chiefly of Ants: and hence the generic name. As yet, however, we have no direct evidence that Ants form the chief food of the Myrmecobius, though it is stated, in Mr. Gould’s “Mammals of Australia,” that wherever this animal takes up its abode, there Ants are found to be very abundant. In the same work the following particulars of the habits of the animal are given from the pen of Mr. Gilbert:--

“I have seen a good deal of this little animal. It appears very much like a Squirrel when running on the ground, which it does in successive leaps, with its tail a little elevated, every now and then raising its body and resting on its hind feet. When alarmed, it generally takes to a dead tree lying on the ground, and before entering the hollow, invariably raises itself on its hind feet to ascertain the reality of approaching danger. In this kind of retreat it is easily captured; and when caught, is so harmless and tame as scarcely to make any resistance, and never attempts to bite. When it has no chance of escaping from its place of refuge, it utters a sort of half-smothered grunt, apparently produced by a succession of hard breathings.

“The female is said to bring forth her young in a hole in the ground or in a fallen tree, and to produce from five to nine in a litter. I have not myself observed more than seven young attached to the nipples.” It is not nocturnal in its habits.

With regard to the range of the genus Myrmecobius, Mr. Gould states that it is very generally dispersed over the interior of the Swan River Settlement, from King George’s Sound on the south to the neighbourhood of Moor’s River on the north, and as far westward as civilised man has yet been able to penetrate. Its species are also found near the Murray and Darling.

This many-toothed Ant-eating Marsupial has always been interesting to geologists, for in the Stonesfield slates of the Oolitic formation of England, which lie low down in the Great Oolite, the lower jaws of an animal have been found greatly resembling those of Myrmecobius. The fossil Amphitherium has the jaws but slightly inflected, and is not without resemblance to insectivorous creatures; but, nevertheless, its similarity to Myrmecobius struck Owen and Lyell many years since.

GENUS DASYURUS.--THE URSINE DASYURE.[117]

Being a great enemy of the poultry and tender rearlings of the colonists of Van Diemen’s Land, this small creature has earned the name of the “Native Devil.” It may be compared to a Bear, with a body about two feet in length, and the resemblance is tolerably correct in the fur, general proportions of the body and limbs, and also in its gait and its actions. The Dasyure, however, has a longer tail than the Bear, and never grows larger than a Badger. It is a short animal, with a round broad head and rather a long snout, and the coarse black fur (brown-black on the head, tail, and beneath) is marked by one broad white band across the chest and by another over the back, close to the tail. The tail is about half the length of the head and trunk. Harris notices that these animals were very common on the British first settling at Hobart Town, and were particularly destructive to poultry, and Mr. Gunn states that they commit great havoc among Sheep, and that notwithstanding their comparatively small size, they are so fierce that they are a match for any ordinary Dog.

As the settlements increased in Tasmania, and the ground became cleared, the animals were driven from their haunts near the town to the deeper recesses of the forests yet unexplored. They were easily procured by setting a trap in the most unfrequented parts of the woods, baited with raw flesh, all kinds of which they will eat indiscriminately and voraciously. They also, it is probable, prey on dead fish and blubber, as their tracks are frequently found on the sands of the sea-shore. In a state of confinement they appear to be untamably savage, biting severely, and uttering at the same time a low yelling growl. A male and female which Mr. Harris kept for a couple of months, chained together in an empty cask, were continually fighting. Their quarrels began as soon as it was dark, as they slept all day, and continued throughout the night almost without intermission, accompanied by a kind of hollow barking, not unlike that of a Dog, and sometimes a sudden kind of snorting, as if the breath were restrained a considerable time and then suddenly expelled. They frequently sat on their hind parts, and used their fore paws to convey food to their mouths. The muscles of the jaws were strong, and they crushed the largest bones asunder with ease.

This Dasyure, like the others of the genus, has the incisor teeth equal, and there are eight of them in the upper jaw and six in the lower. The four canines are large, and there are two powerful premolars in each jaw and on each side. These are succeeded by four molars above and below, and on both sides of the mouth.

The incisor teeth, equal in size, are arranged in a semicircle in the upper jaw, and those of the lower jaw have a corresponding direction, but they are rather the stouter. The canines are well developed, and those of the lower jaw bite in front of those of the upper. They look eminently adapted for stopping and seizing prey, and their carnivorous character is surpassed by that of the premolars and true molars. These last have a triangular grinding surface: the first has four sharp cusps, the second and third have five, and the last, which is the smallest in the upper jaw, has only three. In the lower jaw the last molar is of the same size as the last but one, and has four cusps; and the other molars have much resemblance to those in the upper jaw.

The hind feet have the toes separate and not united by a fold of skin, and there is a rudimentary great toe in this species. The condyle of the humerus is not perforated--as in the Kangaroos, for instance--for the passage of the blood vessels, but is whole, and the outside of the bone is marked by a groove, along which they pass.

Although this Dasyure has the lower jaw inflected, and is a true Marsupial, the resemblance in shape, and in dental and other characters, as well as in its habits, to the Carnivora is striking. Its fierce character and the nocturnal habits add to the similarity; but there are some very peculiar anatomical distinctions. The wrist bones, called scaphoid and lunar, those which are nearest the radius along the first row of carpal bones, are separate in the Dasyure, but in the Carnivora they are united to form one bone. And in the foot there is a peculiarity: for whilst in the Carnivora there is a groove between the heel bone and the astragalus, this is absent in the Marsupial Carnivore, and the articular surface of the bones is continuous.

The Dasyures have a small crest of bone on the top of the skull, which is also seen on a grander scale in the Carnivora. They have, moreover, the zygoma well developed and strong; it bulges outwards and curves upwards, but not to the amount seen in the true Carnivora. The occipital bone is developed as in the non-Marsupial mammals, but its parts, instead of joining together and forming one with age, often remain separate; but this does not appear to occur in all the species of the genus, for Owen, in his wonderful article on the Marsupials in the “Cyclopædia of Anatomy and Physiology,” notices that in the little Dasyurus Maugei the occipital bone presents the usual state of bony confluence. He notices that the Dasyure, in common with some other Marsupials, has the temporal bone permanently divided into its several parts, there being separate squamous, petrous, and tympanic bones; but the petrous and mastoid parts are usually united. This is a reptilian peculiarity, but the tympanic bone of the Dasyure is not without its resemblances to those of birds. The surface on which the lower jaw moves or is hinged, is not composed entirely by the temporal bone, but the malar bone is slightly included, and even the sphenoid comes into the joint.

Another marked character of the Dasyures is, that their hard palates are not whole, but have spaces and perforations, and this denotes a low organisation. This absence of a perfect hard palate is seen in other Marsupials, and especially in the Bandicoots (Perameles).

The angular process of the lower jaw, where inflected or bent in, is triangular and directed upwards, with a blunt point; and the condyle of the jaw is low, being on a level with the molar teeth.

It is remarkable that the Dasyures should have the bones of the leg, the tibia and fibula, so connected together as to allow of a certain degree of rotation on each other, after the fashion of the fore-arm bones. The muscles of the leg are modified for the purpose. This interesting anatomical point recalls one of the great distinctions between the fixed leg bones of man and those of the hand-footed Ape. It is not found, however, in the non-Marsupial mammals, whose habits of life are simulated by the Dasyure; but it is found in the Wombat, a burrower, and in the Koala, Phalangers, and Opossums, which are climbers. In examining the stomachs of the Marsupials, Owen noticed that differences in food and habit are not met by alteration in the shape of the organ, as they are in the higher Mammalia. Thus, the common Dasyure, the insectivorous Bandicoot, and the leaf-eating Phalangers, have a full round, oval, or sub-triangular-shaped stomach, with the right extremity projecting beyond and below the pylorus. The length of the stomach seldom exceeds the height by more than one-third. No cæcum is found in the carnivorous Marsupial, and the intestine is short and wide, being continued, like the intestine of a reptile, along the margin of a single and simple mesentery, from the pylorus to the rectum (Owen). The liver has a gall-bladder in the Dasyure, and there is a pancreas as well as a spleen. The heart is contained in a slight pericardium, as in the other Mammalia. The Ursine Dasyure is found in Van Diemen’s Land only.

There are several kinds of Dasyure, which have been carefully noticed and described. One is called the Long-tailed or Spotted Dasyure,[118] and is about the size of a Cat. The fur is reddish-brown, pencilled with yellow, and is spotted with white both on the body and on the tail. It has a tail as long as the head and body together, and the under parts of the body and the fore-legs and feet are of a dirty yellow tinge. It lives in Van Diemen’s Land, and was, from its shape, at first called a Marten. The teats are six in number, three on each side, and seated within a slight fold only of the skin, so that there is no true pouch.

MAUGE’S DASYURE.[119]

This is a small animal, not larger than a half-grown Cat. It has a longish bushy tail, a broad head, and is somewhat of greyish-yellow colour. There are white spots on the sides of the body and tail. In confinement this little creature is torpid by day, but lively as evening comes on, and it rushes about, with its tail extended, with great rapidity. It is very injurious to the poultry when in a wild state, and is called the Wild Cat in Van Diemen’s Land. A variety of it is the Viverrine Dasyure, which has the head and body spotted with white, the general colour being brown, black, or grey, tinted with yellow, the under parts being white. It has long hairs to its tail; rather large ears, the flesh of which is of a pale pink, as is that of the naked lips, the tip of the nose, and the soles of the feet, the latter being hairless, but covered with small fleshy tubercles. There is no trace of an inner toe to the hind foot, unless it be a slight swelling of the flesh, marking the situation of the rudimentary bone beneath. Both of these animals are to be found in New South Wales and Van Diemen’s Land.

The rest of the Dasyures are widely spread over the continent. The smallest kind is the North Australian Dasyure. Geoffroy’s Dasyure, which has a thin tail and an inner toe to the hind foot, inhabits Western and Southern Australia and New South Wales, is a great killer of the Yellow-crested Cockatoo, and they hunt and kill Mice or Rats as well as any Cat. They have not a pouch.

GENUS THYLACINUS.[120]--THE DOG-HEADED THYLACINUS.[121]

This is a Dog-like, slim, narrow-muzzled animal, with clean and rather short limbs, a foxy head, and a tail about half as long as the body, which in males is forty-five inches in length. It is about the size of a Jackal, and the fur is short, but rather woolly and greyish-brown, faintly suffused with yellow in colour. The fur on the back is deep brown near the skin, and yellowish-brown towards the tip. It has from twelve to fourteen black bands on the body, and the tail has long hairs at the tip only. The eyes are keen, large, and full, and they are black and have a nictitating membrane. The animal walks half on its toes and half on its soles or palms, and thus is a semi-plantigrade, the body being brought nearer the ground than that of the Wolf in running. There is a marsupial pouch, but the bones are mere cartilages. The Dog-headed Thylacinus, or the Zebra-Wolf of the colonists of Van Diemen’s Land, thus described, has often been taken for one of the Carnivora, and certainly there are great resemblances between it and the Dogs. The canine teeth are of large size, but they are recurved at the top, and in the upper jaw are separated from the incisors by a space, into which the point of the lower canine fits when the jaws are closed. This is different in the Dogs, whose lower canine passes on the outer side of the upper one when the mouth is closed. The premolar of the Thylacinus has a small cusp behind, but in the lower jaw the premolars are isolated, and do not form a continuous cutting and masticating ridge. It is also to be remembered that this animal has a peculiar lower jaw, as it is one of the Marsupials, and the angle is inflected. It is a Marsupial, with some structures which foreshadow those of the more highly-developed Dog.

Mr. Harris, who was the first to make this animal known, states that it lives among caverns and rocks, in the deep and almost impenetrable glens, in the neighbourhood of the highest mountains of Van Diemen’s Land. The specimen from which his description was taken was caught in a trap baited with Kangaroo’s flesh; it remained alive but a few hours, having received some internal hurt whilst being secured. From time to time it uttered a short guttural cry, and it appeared exceedingly inactive and stupid, and, like the Owl, had an almost continual motion of the nictitant membrane of the eye. Remains of an Echidna were found in the stomach of the animal. Waterhouse states, on the authority of Mr. Gunn, that these animals are common only in the remoter parts of the colony, and used to be frequently caught at Woolnooth and the Hampshire Hills. They attack the Sheep at night, but are occasionally seen during the daytime, upon which occasions, perhaps from imperfect vision, their pace is very slow. Mr. Gunn also observes that the Thylacinus sometimes attains so large and formidable a size, that a number of Dogs will not face it. That gentleman denies that the tail of the animal is compressed, as has been stated by some authors, and his observations do not confirm the aquatic habits which have been attributed to it. There are cartilages in the place of the marsupial bones; but the pouch is well developed in the female Thylacine, and there are four well developed teats, each four inches long, indicating that it may contain four young ones at a time. The marsupium, or pouch, opens backwards, not, as in the Kangaroos and most others, forwards.

GENUS PHASCOGALE (POUCHED WEASELS).--THE BRUSH-TAILED PHASCOGALE.[122]

This genus includes many species of small Weasel-or Rat-like Marsupials. They are small, insectivorous, and climb shrubs and trees in pursuit of their prey. The largest known is about the size of a common Rat. The brush-tailed kind inhabits New South Wales, South Australia, and Western Australia, and is a pretty little animal, having a long and soft fur, of a grey colour above and white or yellow-white under the body. The eyes are encircled with black, and there is a pale spot above and below the eye, and the hairs are blackest along the middle of the head. The ear is rather large and not furry; the tail is about equal to the body in length, or seven inches to nine inches, and there is a portion near its end of about two inches in length, which is clothed with short, stiff hairs, and the rest has long and glossy hairs, sometimes an inch or two long. An insectivorous little creature, its teeth are modified to meet its diet, and they are less carnivorous than the other Dasyurids. They have the two foremost incisors of the upper and lower jaw larger than the others. There are three premolars in each jaw on each side, and eight molars above and below, which are studded with prickly tubercles, those of the upper jaw having triangular crowns. There are five toes to the fore and hinder extremities, and the inner toe of the latter is in the form of a small nailless prehensile thumb. The brain-case is large and the skull comparatively smooth. The species just noticed is said to enter the stores of the settlers, and it makes a nest in the hollows of the trunks of trees or in the branches. The female has no pouch, but ten teats covered with hair. It is the Tapoa Tafa of White, according to Krefft.

Another species, about six inches long, not including a tail of three inches--the Freckled Phascogale--lives in the Swan River district and at King George’s Sound, being generally distributed over Western Australia. It has the fur freckled with black and white on the head and fore parts of the body. Mr. Gilbert found insect remains in its stomach, and he obtained a female specimen having seven young attached. They were little more than half an inch in length, and quite blind and naked. Above the teats of the mother is a very small fold of skin, from which the long hairs of the under surface spread downwards, and effectually cover and protect the young. This fold is the only approximation to a pouch which has been found in any species of this genus. The young are very tenacious of life, and those just mentioned lived nearly two days attached to the mammæ of the dead mother.

The Yellow-footed Phascogale is a kind which inhabits New South Wales and South Australia, and the White-footed Phascogale and a closely-allied kind live in South Australia and Van Diemen’s Land. In New Guinea, which constitutes a part of the Australian natural history province, there is a black, short-eared, and short-furred kind, about the size of a Rat, called Phascogale melas.

There is a little kind, measuring only three inches in length, with white fur everywhere, except on the upper parts, which are ashy grey; and in Western and Southern Australia there is one which has great ears, very slender limbs, and a short and thick fat tail. It looks like a large-eared, fat-tailed Mouse, and is under four inches in length. All these kinds of Phascogale, except the brush-tailed one, belong to a group with very short hairs on the tail, and are sometimes classified under the name Antechinus, the thick-tailed one being termed Podabrus; and they all have shallow pouches.

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III. THE OPOSSUMS

Prehistoric Opossums--Description of the Animal--Their Teeth--Habits--THE COMMON OPOSSUM--Appearance--Use of its Tail--Food--The Young--How they are Reared--D’AZARA’S OPOSSUM--THE CRAB-EATING OPOSSUM--THE THICK-TAILED OPOSSUM--MERIAN’S OPOSSUM--Pouchless Opossums--Their Young--THE MURINA OPOSSUM--THE ELEGANT OPOSSUM--THE YAPOCK--Classification of Marsupial Animals--Geographical Distribution of the Sub-Order--Ancestry of the Marsupials--Fossil Remains.

VI.--THE OPOSSUM FAMILY.--DIDELPHIDÆ.

The Marsupial animals included in this family are not found in Australia or in Van Diemen’s Land, or in any part of the natural history province to which those countries belong. They are numerous, however, and are now living on the American continent; but formerly some inhabited Europe during that geological period which is called the Eocene. The Opossums are very rat-like in form, the largest species being about the size of a large Cat, but they have the snout more elongated; and in some species in which the individuals are large the body is proportionately stout, and on most there is a comfortable fur, with short and long hair. The tail is almost always very long, nearly destitute of hair, excepting at the root, and is covered with a scaly skin, there being a few scattered hairs. It is a useful organ, for the Opossums hang by it, and it assists them in climbing and descending trees, and in holding on, when they are young, to their parent. The ears are rather large and round, the eyes are placed rather high up in the face, and the long muzzle ends in a naked snout. The legs look short for the body. The feet are naked beneath; there are five toes, and the great toe is more or less opposable to the foot, and acts like a grasping thumb. Each toe is furnished with moderate-sized claws, excepting the inner toe of the hind foot, which is clawless. The Opossums are remarkable for the great number of their incisor teeth, there being ten in the upper and eight in the lower jaw, and they are arranged in a semicircular manner. The upper and two foremost incisors are rather longer than the rest, and are generally separated from them by a narrow space. They are nearly cylindrical and expanded at the tip. The canines are well developed, the upper ones being the largest. There are three premolars on each side of both jaws, and they have two roots, and are compressed and pointed. There is a posterior talon to them. The molars, eight in each jaw, have three roots, and those of the upper jaw have the crown of a triangular form and tubercular, whilst those of the lower jaw are longer than broad, and each has the appearance of five prickly cusps on its upper surface.

Some of the Didelphidæ have no marsupium, or pouch, or it is very slightly developed, and in these particular kinds the young, after having left the nipples, are carried on the back of the mother, retaining their position by twining their tails around hers. The mammæ are numerous: there may be as many as thirteen, an odd one being found in the centre of the ring of the other nipples.

The Opossums are active, sly, and very intelligent in certain things, and their food consists of insects, small reptiles, birds, and eggs. Living for the most part in trees, they secrete themselves in the hollows of the branches and trunks during the daytime and sally forth in the night. They have a moderate-sized cæcum. It must be noticed that the great toe of the hind foot is well developed, has no nail, and enables the creature to grasp, and is thus very useful; and that they walk plantigrade. The ankle and leg have the same movements as in the Wombats, and the same general anatomy. If the members of the family are compared with those of the families which live in the Australian province, it will be found that they most resemble the Perameles and Dasyures. The Opossums may be divided into three groups: those whose pouch is well developed, those in which it is a mere fold, and those which have webbed feet and live in the water, like Otters.

THE COMMON OPOSSUM.[123]

This is a large kind, and is about the size of a common Cat, and its long, large, pointed head, ending in a naked snout, and having eyes encircled in dusky brown fur amongst the white hair and fur of the head, gives it a very cunning and thoughtful appearance. The ears are black. The tail is long and prehensile, the end being white and the rest black, and the legs and feet are brownish. It is a great climber, and uses its tail almost as much as some of its Monkey companions. Running along the branches, it will often suspend itself by its tail, and give a swing and let go, thus launching its body to a distance, and then it catches at the boughs with its feet and unclawed but prehensile hind toe-thumb. In coming down trees it uses the tail to steady itself, and to prevent too rapid a fall; and in climbing, the ever-ready tail prevents mishaps, should the clawed toes not grasp sufficiently. The natural food of this Opossum is probably vegetarian, but it is a great birds’-nester; it will eat roots and fruits, but the early settlers found it very destructive to their poultry, for it catches the birds and sucks their blood, not eating the flesh: consequently, it has been much hunted, and as the fur and skin are sometimes used, the destruction of the Opossum has been great. It is a curious creature, and seems to have gained experience in its struggle with man, and as many stories are told of its cleverness as there are about Reynard the Fox and the Indian Jackal. It will sham death in a most persevering manner, and is at the same time very tenacious of life.

The skull has strong temporal ridges, which form a sagittal crest, and the arch of the zygoma is well grown. The animal has a longer facial part of the skull and a smaller brain-case than the other Dasyures, and the brain has large olfactory or front lobes. The cerebral hemispheres are small, and there are no convolutions. This is essentially a North American animal, and is found from Mexico to the Southern States inclusive.

The female brings forth from twelve to sixteen young at a time, and her nest, which is formed of dry grass, is usually at the root of a tree or bush. When first born, the young are said not to be more than a grain in weight, and blind, naked, and shapeless. They find the teats in the mother’s pouch, unless she places them on to them with her mouth, and they cling on so as not to be separated except by violence. In about five days, so rapid is their growth, they have reached the size of a Mouse, and all their parts are developed. They then leave the pouch, and return to suckle and when danger appears. During this time the female shows great attachment to her young; and Mr. Waterhouse, from whose work these descriptions are taken, states that she will suffer any torture rather than permit the pouch to be opened.

AZARA’S OPOSSUM.[124]

This is a smaller animal than the common or Virginian Opossum, but its tail is long in proportion to its body. It is the South American representative of its larger fellow species, and is found over a very wide extent of country. It was noticed by the celebrated naturalist D’Azara in Paraguay; Mr. Darwin found it at Maldonado, La Plata; and specimens have been obtained from the Brazils, Santa Fé de Bogota, and Bolivia. This is because it is not entirely a forest animal, but is found occasionally in the open country. It may be distinguished from the common Opossum by three distinct black marks on its head, by its large tail, one-third of which is covered with fur like that on the body. The rest of this important member is scaly, with small hairs springing from between, the scales being black in the second third, and white at the tip in colour. The habits of this Opossum are nocturnal, and it lies concealed by day in burrows in the ground or in thickets. At night it climbs trees to feed upon fruits and birds’ eggs. It will chase and catch sleeping birds, and suck their blood like a Weasel.

THE CRAB-EATING OPOSSUM.[125]

A small Opossum, with a long black tail tipped with white, and a dull-coloured fur to its body, lives in Brazil and Guiana, and has a very omnivorous disposition. Preferring swampy situations, it lives mostly on the trees, hunts small birds and insects, and even catches a reptile now and then, but its fondness for the Crustacea of the swamps is proverbial, and hence its name of Crab-eater.

Another species is interesting from being found in the part of California which adjoins Mexico. The Short-headed Opossum also belongs to this group, and is from the same locality. Besides these, there are several smaller pouch-bearing Opossums, without the long hair of those just mentioned, and they are from Brazil, Guiana, and Surinam--for instance, the Quica, the Naked-tailed, and the Four Spotted kinds. The Philander Opossum is a bird-hunter, and lives in Surinam.

The next group of Opossums have no pouch, but there may be folds of the skin protecting the mammæ.

THE THICK-TAILED OPOSSUM.[126]

As its name implies, this pouchless Opossum has a very thick tail. Moreover, it has smaller ears than the other Opossums, and has a short head and short legs. The fur is made up of harsh hairs, which are close to the body, and there is but little under fur. Its colour is yellow-brown, but the eye and muzzle are brownish, and the tail, with the terminal two-thirds, is black, with the exception of a small white spot at the end. It inhabits Brazil and Paraguay, and extends southwards to the River Plate. One of the Opossums was kept by D’Azara, who found it quiet, tame, and stupid; but having been fed on raw meat, and a parrot happening to come too close, it killed the bird in a moment. There are folds of skin in the lower part of the abdomen, but no pouch, and there are six mammæ.

Another of the Opossums is called Merian’s Opossum, or Didelphys dorsigera, and it inhabits Surinam. It was described by Madame Merian in 1717, who represented it in her great book on insects with its young clustered on its back and hanging on to the mother’s tail, which was curved over its back, with their little tails.

It is very curious that the young of these pouchless Opossums should resemble those of the whole order in being comparatively little advanced in their development at the time of their birth. The young are at first strongly attached to the teats of the mother, and when they are sufficiently strong and grown to leave them, occasionally she takes them off from the nipples and places them on her back. Here they cling on with their tails to hers. Hence the name of back-bearing, or Dorsigera, which is given to this kind.

It was at first supposed that this method of carrying the young was restricted to this species, but subsequent experience has shown that several kinds do the same thing.

Two or three other species of Opossum are interesting from their small size and habits. Thus the Murina Opossum (Didelphys murina), with a very long tail, inhabits Guiana, Brazil, Peru, and Mexico. The body is about five inches in length, and the tail is either slightly longer or about the same. Yet this little thing attacks birds and insects; it burrows in the ground, and climbs trees to get its insect food.

The Elegant Opossum (Didelphys elegans), of Chili, is still smaller than the last, and frequents the thickets growing on the rocky hills near Valparaiso. They are numerous, or were so when Mr. Darwin observed them, and are easily caught in traps baited with cheese or meat. The tail appeared to be rarely, if at all, used as a prehensile organ; yet they could run up trees with some degree of facility. It is an interesting fact that some of the smallest Opossums prey upon Lizards and Snakes as large, and even heavier, than themselves.

The last section of the Opossums contains the Water Opossum.

THE YAPOCK.[127]

This animal has a perfect pouch, and has large hind feet, the toes of which are united by a web. The fore feet are moderate-sized, and the pisiform bone is unusually long. Its habits are aquatic. The Yapock has large naked ears, and a long, almost naked, tail, and is altogether rather larger than the common Rat. Its method of life is very much the same as that of the Otter. It is a good diver, and feeds upon crustaceous and other aquatic animals. It is a native of Guiana and Brazil.

* * * * *

The Marsupial animals assume the general shape and habits of many orders of Mammalia which have no marsupium, and which live in the other great natural history provinces. Thus there are Marsupial animals like Dogs, Rats, Squirrels, Flying Squirrels, Deer, &c. They have, therefore, many methods of life as a group, and, as might be expected, the brain and nervous system present many differences in them. In all, the front lobes of the brain which deal with the sense of smell are very large, and in some, such as in the Carnivorous Marsupials, they are exposed, and not covered by the main mass of the brain. In the Kangaroos, however, these olfactory lobes are hidden more or less. These last also have well-marked convolutions on the brain which are nearly wanting in those first mentioned.

The Marsupial animals just considered have been classified to a certain extent during their descriptions, but it is necessary to recapitulate. They are arranged in groups of genera or species, or into families. They are as follows:--

ORDER MARSUPIALIA.--SUB-ORDER MARSUPIATA.

{ Genus Macropus Kangaroos.[128] Family MACROPODIDÆ { „ Dendrolagus Tree Kangaroos. { „ Hypsiprymnus Potoroos. { „ Hypsiprymnodon The Hypsiprymnodon.

„ PHASCOLOMYIDÆ „ Phascolomys The Wombat.

{ „ Phascolarctus The Koala. { { The Cuscus. „ PHALANGISTIDÆ { „ Phalangista { Dormouse Phalanger. { { Phalangers. { „ Petaurus Flying Phalangers. { „ Tarsipes Tarsipes.

„ PERAMELIDÆ { „ Perameles Bandicoots. { „ Chœropus Chœropus.

{ „ Myrmecobius Ant-eaters. „ DASYURIDÆ { „ Phascogale Phascogale. { „ Dasyurus Dasyures. { „ Thylacinus Dog-headed Thylacinus.

„ DIDELPHIDÆ { „ Didelphys Opossum. { „ Chironectes Yapock.

The Macropodidæ, Phalangistidæ, Peramelidæ, and Dasyuridæ are found living somewhere or other in the Australian distributional province, which includes the mainland, Tasmania to the south, and the Molucca and Arru Islands to the north, bounded by the Straits of Lombok, and Celebes, New Guinea, New Ireland, Timor, Amboyna, Banda, and Waigeoe. Each family is not represented fully, however, in all the remarkably separated divisions of the province. Thus the genera Macropus and Dendrolagus of the first family, Petaurus and Phalangista of the third, Perameles of the fourth, and Phascogale of the Dasyuridæ have been found in New Guinea; but in other islands, such as Celebes, and in those from Lombok to Timor, the genus Cuscus alone is represented. In the Moluccas, Cuscus and the genus Petaurus are found. In Van Diemen’s Land about one-half of the species are peculiar to the island, and the remainder are found also on the eastern districts of the mainland. It has Kangaroos, Potoroos, Wombats, Phalangers, Bandicoots, and three out of the four genera of Dasyuridæ. Western Australia, which is such a remarkable botanical province, and is so separated by desert and sand from the east, has numerous Kangaroos, Potoroos, Phalangers, Bandicoots, Phascogales, Dasyures; and, in common with South Australia, a Chœropus, whilst the genus Tarsipes is peculiar to it. The Wombat is found in Van Diemen’s Land and some of the islands in Bass Strait. It is found in the south and east of the mainland of Australia, but not to the west and north. Mr. Waterhouse notices that the Marsupials of the eastern districts are for the most part distinct from those of the opposite side of the continent, there being, when his great work, which has been so constantly referred to in this description, was written, but eight species out of upwards of sixty inhabiting the two provinces. South Australia is the habitat of more common species than elsewhere. The northern part of Australia has more species peculiar to it than the other divisions, and some of its Dasyuridæ especially, and species of Cuscus also, are found in the Arru and other islands to the north. The metropolis of the sub-genus Cuscus is in the Moluccas, where two species are widely distributed, or one is restricted to certain islands.

The other divisions of the genus are represented by the Vulpine Phalanger, an animal with long loose fur, which inhabits New South Wales, Western Australia, and North Australia; by Cook’s Phalanger, of New South Wales and Van Diemen’s Land. The genus Perameles, the Bandicoots, has species in Van Diemen’s Land, Australia, New Guinea, and in the Arru Islands, and the genus Petaurus has a corresponding distribution. The Didelphidæ are found in the United States, California, Mexico, Peru, Guiana, Brazil, Paraguay, Banda Oriental, and Chili; and Brazil is the country where they abound the most in species and individuals, the number diminishing to the north and south.

The Marsupials have a great ancestry, and some of them lived when the continents and oceans of the earth were in very different relative positions to those they now occupy. Indeed, it is most probable that the fossil remains of the most ancient mammal belong to this order. There is a small double-fanged molar tooth of a mammal which was found by Plieninger, in 1847, contained in a jumble of shells and of the remains of reptiles and fishes in strata beneath the Lias formation of Diegerloch, near Stuttgart. It and another which was discovered close by, by the same professor, belonged to animals which were dead when this topmost stratum of the Trias, immediately beneath the Lias, was being formed. They are Triassic in age, therefore, and they somewhat resemble the back teeth of a fossil which was found subsequently in the Purbeck strata of England, and which evidently belonged to a Marsupial more or less resembling the existing Kangaroo-Rats or Potoroos, of the genus Hypsiprymnus. Later on, Professor W. Boyd Dawkins, F.R.S., discovered a small tooth belonging to the same extinct genus as that which included Plieninger’s fossil, namely, Microlestes; and its resemblance to one of Hypsiprymnus is even greater. Its position was high up in the Trias of Watchet in Somersetshire. Mr. Charles Moore, of Bath, had previously found many specimens of teeth of the same family in a fissure, down which they had been washed by the Triassic sea.

A lower jaw of a small Mammal was found in the Trias of North America by Emmons; and it has on one side three incisors, one long canine, then a diastema, three premolars, and seven molars with three points. It is therefore one of the Myrmecobius group.

After the age of the Trias, when there was much continuous land surface, Europe was broken up into a coral island tract, during the age of the collection of the Jurassic deposits. The islands were tenanted by many small Marsupials, four species of which have been discovered in the deposits of Stonesfield slate at the bottom of the Great Oolite. They belong to the extinct genera Amphitherium, Phascolotherium, and Stereognathus, and the first somewhat resembled the Myrmecobius of recent times; but all that can be said is that they belonged to Marsupial animals. Piled on the Stonesfield slates are many hundred feet of strata, and high up amongst them, in the Swanage and Purbeck districts, are deposits in which Messrs. Brodie and Beckles have found portions of the skeletons of numerous insectivorous Marsupials, of which the genera Spalacotherium, Plagiaulax, Triconodon, and Galestes are the most important. They were small, as a rule, and there has been much debate regarding their affinities with modern insectivorous forms, and they are still surrounded with doubt.

The appearance of the Mammalia without pouches took place in the Eocene age, and in the Old and New World, and contemporaneously with them lived in France a kind of Opossum, some of whose bones were found in the strata of Montmartre, near Paris; and in later Tertiary strata other relics have been found. These are the only instances of a fossil Didelphid occurring out of the New World; and there, where the Opossums are now characteristic animals, they were present in the last geological age, for in the Brazilian latest deposits remains of several species of Didelphys have been found. Remains of these fossil Opossums have been found in the North American Pliocene deposits. The more ancient deposits of Australia have not yielded the remains of any of the animals which are now so peculiar to the province, but in the bone caves of the Wellington Valley, some two hundred and ten miles west of Sydney, Sir Thomas Mitchell discovered a mass of bones, forming a breccia with limestone, which contained numerous and most interesting Marsupial remains. In deposits of the same late age, and in bogs and gravels in Queensland, other remains were found. They were described by Sir R. Owen in one of his greatest works, and they belong to the Australian families of Marsupials, and not to the American Didelphidæ. As was usual elsewhere before the appearance of man on the earth, and contemporaneously with him for awhile, many of the kinds which resemble more or less those now living, or would be classified in the same family, and perhaps in the same genus, are gigantic. Owen distinguished among the bones those of large fossil Marsupials which belong to the Macropodidæ, and which may be arranged as subdivisions of the genus Macropus or Kangaroos, and of a powerful creature called Thylacoleo, or Pouched Lion, which must be admitted as a new section of the Macropodidæ, and whose habits were probably carnivorous, although there is much diversity of opinion on the subject, some of the most distinguished anatomists believing the creature to have been of an innocent disposition, although appearances are much against it. It is more closely allied to Plagiaulax, of the English Purbeck beds, than to any other form, and they well fit in between the genera Macropus and Hypsiprymnus.

A huge Marsupial, with a skull three feet in length, with teeth, in front especially, on the Kangaroo plan, and with longer fore limbs and shorter hind ones than the last-named animal, was described by Owen. The pelvis, however, has but two sacral vertebræ, and its ilio-pubic process would ally it with the Macropodidæ. This Diprotodon was an herbivorous animal, and was of the size of a Rhinoceros. This great Marsupial had fore limbs which possessed the power of rotation, and it was not without some characters which are seen amongst the Wombats. It appears to have had a great range, for its remains have been found in the caverns in the Wellington Valley, at Welcome Springs, South Australia, Hergolt’s Springs, 500 miles north of Adelaide, near Melbourne, in the valley of the Condamine River, and widely over Queensland. A slightly smaller animal, called the Nototherium, also existed with the larger one.

The species of this genus have no lower incisive tusks, and a very short chin; the angle of the jaw is curved inwards, and there were only four molar teeth on each side in both jaws, and they were with two strong roots or fangs. It was probably one of the Macropodidæ. Others of this family are allied to Dendrolagus, and form the genera Protemnodon and Sthenurus. The Wombat was represented in the age of the great Marsupials; and both large and small species, one being of the size of the Tapir, have been described from bones and teeth which were found in the cave deposits of Australia. Remains of a Marsupial animal, probably of the Vulpine Phalanger, were found in the same caves, as were also some referable to the genus Perameles, or Bandicoots, and to the Potoroos. Several fossil species of the family Dasyuridæ have been found in the Australian caves, and one of them is referable to a section of the genus Dasyurus, which at present is restricted to Van Diemen’s Land, it being somewhat like Dasyurus ursinus; moreover, probably, there was a species of Thylacinus present also. So far as is known from the researches of Owen amongst this wonderful cave fauna, no members of the family Didelphidæ occur there. They were American then, as they are now.

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IV. SUB-ORDER--MONOTREMATA.[129]

THE PORCUPINE OR LONG-SPINED ECHIDNA AND DUCK-BILLED PLATYPUS.[130]

Why the Monotremata are formed into a Sub-order--The lowest of the Mammalian Class--THE PORCUPINE OR LONG-SPINED ECHIDNA--An Ant-eater, but not an Edentate--Its Correct Name--Description of the Animal--Habits and Disposition--Manner of Using the Tongue--Where it is Found--Anatomical Features: Skull, Brain, Marsupial Bones--The Young--Species of Van Diemen’s Land and New Guinea--THE WATER-MOLE, OR DUCK-BILLED PLATYPUS--The most Bird-like Mammal--Various Names--Description--Their Appearance and Movements in Water--Their Burrows--Habits of an Individual kept in Confinement--Used by Natives as Food--How they are Captured--The Young--A Family in Captivity--the Snout--Jaws--Teeth--Tongue--Fore and Hind Feet--Heel--Spur--The Shoulder Girdle--Breastbone--Concluding Remarks on the Sub-orders--Postscript on the Monotremes.

THE PORCUPINE OR LONG-SPINED ECHIDNA.

This animal is the first example of some Marsupial beasts which are separated into a sub-order, because, in addition to the marsupial bones, there are some internal points of construction which are more bird-and lizard-like than those of the Kangaroo tribes. It contains animals which are the lowest of the Mammalian class, and are found only in the Australian natural history province. The Porcupine Ant-eater, as its name implies, has somewhat the shape of a Hedgehog or Porcupine, and it is fond of burrowing with its peculiar limbs, as well as of eating Ants with the assistance of its long tongue. But its internal anatomy and the construction of the skeleton differ from those of the true Ant-eaters, which belong to the order Edentata. It was called Ant-eater by its first describer (Shaw) in 1792, but a few years afterwards it was decided to belong to the same group as an animal about to be described--the Duck-billed Platypus, or Water Mole--and Cuvier, whilst believing that they both belonged to a peculiar order, separated this false Ant-eater from the Water Mole as a species and genus. He called this Hedgehog-like creature Echidna, from the presence of a spur on the heel, which is perforated, and which was erroneously supposed to be poisonous, like the fang of a Viper (Ἔχιδνα). The correct name is the Long-spined Echidna, or the Porcupine Echidna (Echidna hystrix).

The creature greatly resembles a Hedgehog with a very long snout, at first sight, but a slight examination will show that it differs much from the insect-eating and spiny little Hystrix. The Echidna is about a foot in length, and the upper part of its short body is covered with strong spines, and the rest is hairy, the front of the head, and the long, slender, and tapering snout being naked. The legs are short and strong, and the five toes of the fore leg have large and strong claws. This is in order to permit the creature to bury itself in sand and soft earth quickly, and this operation is assisted by a broad and rounded nail on the inner toe of the hind foot and by large claws on the other toes, and especially by a long nail to the second toe. A very long and flexible tongue enables the creature to catch prey. There are no teeth. The skull, when the skin and flesh have been removed, has a very pear-like appearance. It is a great burrower, and manages to get out of the way of observers as soon as is possible, for working actively with its strong limbs and claws, it pokes its snout into the earth and soon gets out of view. Ants are its favourite food, and they are captured in the same way as by the Great Ant-eaters belonging to the Edentata: for in both there is a long slimy tongue, which can be poked far out of the mouth into Ants’ nests. The saliva required to make the tongue sticky comes from large glands under the lower jaw from the ear on to the fore part of the chest. When the Ants have collected on the sticky tongue it is taken into the mouth, and they are swallowed. The absence of teeth is made up by the presence of horny spines on the palate and tongue, which look backwards, and these crush and direct the food to the throat. It is an apathetic and stupid animal, and usually tries to get out of the light, and it will lie and roll itself up, but not so successfully as a Hedgehog. One of the first which was seen was attacked by the Dogs of two of the travellers, Bass and Flinders, whose names are so familiar from places having been named after them in Australia. The Dogs did not come off victorious, for the new animal burrowed in the loose sand, but not head foremost; it sank itself directly downwards, and left its prickly back just on a level with the surface.

An Echidna was watched, so that the manner in which it could use its tongue was observed. Ants could not be had, but a diet of chopped-up eggs, liver, and meat was readily received, and it was noticed that the tongue was used in the same manner as that of the Chameleon, by simple protrusion and bringing in, and also as a mower moves his scythe, it being curved sideways, and the food swept into the mouth. The Echidna is fond of water and milk, which are licked up by a rapid putting out and drawing in of the long tongue.

Gerard Krefft says that they are usually found in mountain ranges, and among rocks in the Lower Murray district. He failed to feed them on Ants and their eggs. On hen’s eggs they fed for a time, and liked bread-and-milk. He has reason to believe that they live on grass also, as those whose stomachs and intestines he examined had fed on herbs and grasses. The spur on the heel is not used as a weapon of offence.

It inhabits Australia, and has been found as far north as the Bellenden Plains, Queensland, about 18° south latitude. A specimen has also been captured at Cape York, and others at Plain Creek, Queensland. It is not found in Van Diemen’s Land.

With regard to the anatomy of the Echidna, it may be said that the long muzzle and the very slender lower jaw give the skull a bird-like look which is increased by the swollen and ball shape of the brain-case. The bones of the skull remain imperfectly united for some time, and then they are united by plain lines of junction, and not by jagged sutures. The shoulder and the bones of the upper part of the chest resemble those of the Water Mole, and will be noticed in its description. The brain of the Echidna weighs about one-fiftieth of the whole body, and the hemispheres do not conceal the cerebellum. There are three convolutions behind, and in front of them is a large one bent on itself, and on its outside are some oblique folds. The sense of smell, evidently acute in the Echidna, is assisted by a large development of the olfactory lobes of the brain and their nerves.

The Echidnas have large marsupial bones. They have not a true pouch, but only a rudimentary one, or rather an infolding of the skin, during the breeding season, in the female. The orifices of the teats are situated beneath the level of the skin, and inverted; and as the surrounding parts swell under the influence of suckling, there is a little cavity made, at the bottom of which are the so-called nipples. They are really little depressions with hair around them. The young Echidnas are placed in this temporary cavity by the mother, and help themselves by placing their snouts in the small depressions leading to the milk gland. Captain Armit says that some force is required to get the young out of the pouch, and that there is probably a muscular ring to it. They are at first very small. When about a month or so old, the hinder parts of the young may be seen sticking out of the region of the fold, and at three months the body may be observed, the animal still adhering by its snout. When the prickles of the young begin to harden, the old one turns them out into the world. (But see Postscript, p. 234.)

A short-spined Echidna (Echidna setosa) inhabits Van Diemen’s Land, whose hair is sufficiently long to hide most of the spines, but little is known regarding its habits. Quoy and Gaimard, two French naturalists, kept one for a month, and it took no food, but after that time it began to lap and to eat a mixture of flour, sugar, and water. It burrowed very rapidly, and got to the bottom of a large can full of earth and plants in the course of a few minutes, and it was assisted in this by its snout.

A species of Echidna has been found in the north of the Island of New Guinea, at the Mont des Karous and Mount Arfak, at an altitude in the first place of 1,150 yards. It likes the rocky broken ground, and is unknown on the sea coast. The natives call it “Nokdiak,” and hunt it for the flesh. As the animal burrows well, the natives dig down about a yard in different places, and generally cut across one of the underground runs. It has been described, and has been named after the explorer, M. Brujn. It is more robust and larger than the species from Australia and Van Diemen’s Land, has a very long snout--three times the length of the head--a short tail, and is black in colour with white points. The fur is plentiful, and like velvet, whilst the spines are scanty, and about midway in strength between those of the two Australian kinds. The number of nails on the fore and hind feet is singular in this New Guinea Echidna, for there are three on each instead of five. The tongue of the species is longer and more spiny; moreover, the number of vertebræ differs in this new kind. There are seventeen dorsal instead of fifteen, and there is one caudal more than in the others. The spiny pimples on the tongue and palate, so well developed in this Echidna, have tempted Professor Gervais to include it in a new genus, Acanthoglossus; but it is as well to retain the old name, so that the creature is called Echidna Brujnii. Another species has been found in the south of New Guinea, at Port Moresby, which is distinguished chiefly by the long, thin, cylindrical form of the quills, and the stiff, flat, hair-like bristles on the face. The tint of the flattish bristles covering all the body and limbs, except the back, is brown; on the back are long cylindrical spines, some white and others black. There are five claws to each foot, and the second hind toe is said to be the largest. The fore limbs are short, stout, and strong. It has been named Echidna Lawesii (Ramsay), after its discoverer. All these animals can roll themselves up.

THE WATER MOLE, OR DUCK-BILLED PLATYPUS.[131]

Like most of the other objects of natural history found in Australia and the neighbouring islands, the Water Mole is very singular in its construction, nature, and habits. It is of all animals that suckle their young the most like a bird, and it really deserves the title, from its external appearance of half beast, half bird. As its shape and method of life are peculiar, it has received several names, such as the Water Mole, the Flat-footed, Duck-billed Platypus, the Bird-beaked quadruped, and the Paradoxical Bird-beaked animal. It is very fond of the water and also of burrowing in the ground, and, of course, is admirably adapted for these pursuits: hence its construction relates to them to a certain extent, and also to that of the animals of which it was, as it were, a continuation in the scheme of nature.

The Ornithorhynchus anatinus has a rather flat body of about eighteen inches in length, and the head and snout greatly resemble those of a Duck, whilst the tail is short, broad, and flat, and resembles that of a small Beaver, but is shorter. The feet are webbed and flat, and the greater part of the creature is covered with a short dense fur of a dusky brown colour, darker on the upper and paler on the under parts of the body. A slight examination of the habits of the animal will explain the necessity for observing it a little more closely. Mr. Bennett describes his first interview with one shortly after his arrival in Australia. He writes: “We soon came to a tranquil part of the river, such as the colonists call a ‘pond,’ on the surface of which numerous aquatic plants grew. It is in places of this description that the Water Moles are most commonly seen, seeking their food among the aquatic plants, whilst the steep and shaded banks afford them excellent situations for excavating their burrows. We remained stationary on the banks, waiting their appearance with some degree of impatience, and it was not long before my companion quietly directed my attention to one of these animals, paddling on the surface of the water, not far distant from the bank on which we were then standing. In such circumstances they may be readily recognised by their dark bodies, just seen level with the surface, above which the head is slightly raised, and by the circles made in the water round them by their paddling action. On seeing them, the spectator must remain perfectly stationary, as the slightest noise or movement of his body would cause their instant disappearance, so acute are they in sight or hearing, or perhaps both; and they seldom appear when they have been frightened.” On ordinary occasions they do not remain more than a minute or two at a time on the surface of the water.

A burrow of an Ornithorhynchus, which Mr. Bennett opened, had its entrance on a steep part of a bank, situated about one foot from the water’s edge, and concealed among the long grass and other Plants. “This burrow ran up the bank in a serpentine course, approaching nearer to the surface of the earth towards its termination, at which part the nest is situated. No nest had yet been made in the termination of the burrow, for that appears to be formed about the time of bringing forth the young, and consists merely of dried grass, weeds, &c., strewed over the floor of this part of the habitation.” The expanded termination measured one foot in length and six inches in breadth, and the whole length of the burrow was twenty feet. Besides the entrance before alluded to, it appears there is usually a second opening into the burrows below the surface of the water, communicating with the interior, just within the upper aperture. A burrow subsequently examined by Mr. Bennett terminated at a distance of thirty-five feet from the entrance; and that gentleman stated that they have been found fifty feet in length.

From the burrow first opened by Mr. Bennett a living female was taken, and placed in a cask, with grass, mud, water, &c., and in this situation it soon became tranquil, and apparently reconciled to its confinement. On his return home to Sydney, Mr. Bennett determined to indulge it with a bathe; and with this view, when he arrived in the vicinity of some ponds, he tied a long cord to its leg. “When placed on the bank, it soon found its way into the water, and travelled up the stream, apparently delighting in those places which most abounded in aquatic weeds. When diving in deep and clear water, its motions were distinctly seen: it sank speedily to the bottom, swam there for a short distance, and then rose again to the surface. It appeared, however, to prefer keeping close to the bank, occasionally thrusting its beak into the mud, from whence it evidently procured food, as, on raising the head, after withdrawing the beak, the mandibles were seen in lateral motion, as is usual when the animal masticates. The motions of the mandibles were similar to those of a Duck under the same circumstances. After feeding, it would lie sometimes on the grassy bank, and at others partly in and partly out of the water, combing and cleaning its coat with the claws of the hind feet. This process occupied a considerable time, and greatly improved its sleek and glossy appearance.”

The Water Moles are said to have a peculiarly fishy smell, more especially when wet, which probably proceeds from an oily secretion. They are used by the aborigines for food; “but it is no particular recommendation of them,” Mr. Bennett remarks, “to say they are eaten by the native Australian, as nothing in the shape of provender comes amiss to him, whether it be Snakes, Rats, Frogs, Grubs, or the more delicate Opossum, Bandicoot, and Flying Squirrel.”

The Ornithorhynchus is captured by the natives when in its burrow. They first examine the neighbourhood of the burrow, to ascertain, by the presence of recent footmarks on the soil, whether it is inhabited, and if the examination proves satisfactory, they proceed to dig holes with pieces of sticks from the surface of the ground into the burrow, at distances from each other, until they discover its termination, when the Australians consider themselves exceedingly fortunate should they find the young, since they are regarded as a great delicacy.

The young have been found in their nests by Mr. Bennett about one inch and seven-eighths in length, in the early part of December, and near the end of the same month he found young Water Moles of ten inches in length. These latter were kept alive for nearly five weeks, and their habits whilst in captivity are described in detail in his paper, which is illustrated by some admirable figures, showing their various attitudes, &c. The young were allowed to run about the room; but an old Ornithorhynchus in the possession of our author was so restless, and damaged the walls of the room so much by her attempts at burrowing, that it was found necessary to confine her to the box. “During the day she would remain quiet, huddled up with her young ones; but at night she became very restless, and eager to escape. The little ones were as frolicsome as puppies, and apparently as fond of play; and many of their actions were not a little ludicrous. During the day they seemed to prefer a dark corner for repose, and generally resorted to the spot to which they had been accustomed, although they would change it on a sudden, apparently from mere caprice. They did not appear to like deep water, but enjoyed exceedingly a bathe in shallow water, with a turf of grass placed in one corner of the pan; they seldom remained longer than ten or fifteen minutes in the water at one time. Though apparently nocturnal, or at least preferring the cool and dusky evening to the glare and heat of noon, their movements in this respect were so irregular as to furnish no grounds for a definite conclusion. They slept much; and it frequently happened that one slept whilst the other was running about; and this occurred at almost all periods of the day. They climbed with great readiness to the summit of a book-case, and thus, by means of their strong cutaneous muscles and of their claws, mounting with much expedition to the top. Their food consisted of bread soaked in water, chopped eggs, and meat minced very small, and they did not seem to prefer milk to water.”

Mr. Foulerton states that the natives are seldom successful in catching the Water Moles alive, although in some places in the rivers and creeks of New England they are so numerous that from fifteen to eighteen have been shot in an afternoon. In the dark, rocky, shady rivers they may be seen at any time of the day, but in more open places seldom before sunset. He failed to see any young ones, and believes that they keep them concealed until near their maturity. They are very active in the water, and are more frequently under than above the surface. He never saw one leave the water, and states that they made very poor progress on land. As a rule they are to be found in good fellowship with the Australian Water Rat (Hydromys chrysogaster).

The young Water Moles are naked, and have a short beak with fleshy and smooth edges, and this conformation enables them to seize the space on the mother whence the milk comes, for there are no nipples. Their tongue is large and assists in the sucking also.

The most curious feature in the Ornithorhynchus is the snout in the form of a beak. This is flat and broadest in front where it is rounded. It is hard, and is covered with a skin full of pores, and on each side this skin overlaps the sides to form a kind of fringe or flexible cheek, and this free membrane is carried round the front. Where this skin comes to the head, it forms a wide fold, which flaps over the front of the head and throat, and is a capital protection when the creature is grubbing in the wet banks or burrowing, and evidently protects the face and the eyes from injury. The nostrils are close to the extremity of the snout. In the lower jaw, or part of the beak-like snout, there are some ridges, which mark it crosswise from the mouth to the outside, and corresponding structures may be noticed in a Duck, their use being to provide grooves or spaces through which water may pour out of the mouth when the creature is feeding on soft mud and wet substances. Inside the mouth there is a pouch in the cheek, one on each side, and this is to retain food. It has four teeth in the upper and four in the lower jaw, but they are horny and made up of tubes; the front ones are long and narrow, and the others are oblong and oval in form, with a hollow crown. Moreover, the tongue, as in some reptiles, has horny teeth on it. The eyes of the creature are small and brown, and are situated close to the beak, and they look upwards. The ear is hidden by the fur, but it is none the less sharp of hearing. As may be gleaned from the notice of its habits, the animal has great power of swimming but not much of running, although the limbs are short. The fore-feet have five toes, nearly equal in length, the first being rather the shortest, and all have solid and rounded claws. The toes are webbed, and the fold of skin even extends in front of the claws when swimming is going on, but is folded back in digging. In the hind-feet the web does not extend farther than the base of the claws, and there is a spur on the heel, which is movable and sharp. It is found on the adult males in perfection, and it may be useful as well as ornamental. On carefully examining the under and lower part of the body, the milk or mammary glands are to be seen, and there is no proper nipple; but when suckling, the swelling of the gland produces an eminence, which can be grasped by the wide, open, and soft beak of the young.

It was thought that this bird-like creature laid eggs, but the point was not easy to determine. (See Postscript, page 234.) It has a double uterus, leading to the common canal, called urogenital, and this ends in the common outlet. The Ornithorhynchus and Echidna have an arrangement of the bones of the shoulder and chest, which resembles to a certain extent that of the Lizards and of the Ichthyosaurus, and the annexed engraving will explain the position of the bones. Indeed, the most important peculiarity in the skeleton of the Monotremes is that of the shoulder-girdle and upper part of the chest; for a bone, the merest vestiges of which are noticed in some of the Mammalia, occurs, that is of some importance in the great groups of birds and reptiles, which are lower in the animal scale than the Vertebrata already described. In all the animals described hitherto, and including the Marsupiata, the large arm bone (humerus) is jointed at the shoulder with the blade bone, or scapula. The socket in this bone, which receives the somewhat ball-shaped top of the humerus, in order to permit of very general motion, is a part of the scapula, and is called the glenoid cavity; but in the Monotremes a bone called the coracoid joins with the scapula, and forms part of the socket; moreover, this coracoid is long enough to reach the breast bone, or sternum. The breast bone in the Mammalia hitherto noticed consists of an expanded part at its fore end (in the usual position of quadrupeds), or at its top in man, called the manubrium, and of some smaller pieces, which form the front bone of the chest and reach to the belly, having ribs attached to them on each side. This is the state of things in the Monotremes; and the coracoids are attached to the manubrium, one on each side. In other Mammalia it is the collar bone which is jointed there. In addition to these breast bones in the Monotremes, there are other bones in front, or between the neck and the top of the manubrium. Firstly, there is a bone in the shape of a =T=: the lower point is on the breast bone, and the cross-bar supports a collar bone on each side, which reaches outwards to the blade bone. Secondly, there is a bone on each side in front of the coracoid, reaching forwards towards the neck. This is called the epicoracoid. Some of these bones, now noticed for the first time, are more or less common to birds, reptiles, and amphibians.

There are some other anatomical points which ally the Monotremes to the reptiles. For instance, the peg on the second, or axis vertebra of the neck, is not fixed to the bone by true bony matter, and some of the ribs which exist in the neck in the Monotremes are separate from the vertebræ until late in life, or altogether. And the cavity for jointing of the thigh bone with the pelvis (the acetabulum) is not perfect, there being a part of it not filled with bony matter.

The ear is singularly simple in its construction in this sub-order, and the cochlea is not coiled into a spiral; moreover, there is no external ear.

The hemispheres of the brain, which are convoluted in the Echidnas, are smooth in the Ornithorhynchus, and in both the central commissure, or corpus callosum, just exists, whilst the anterior one is large. The Ornithorhynchus inhabits Van Diemen’s Land and Australia, as far north as Queensland inclusive.

The Echidna and the Ornithorhynchus belong to a sub-order of the Marsupialia which, whilst it has some structures resembling those of the sub-order of Marsupiata, possesses others which link it with the birds and reptiles. This sub-order is the lowest amongst the Mammalia, and the animals which are included in it have the following peculiarities:--The marsupial bones are present, the uterus is double, and the young are not nourished when within the parent by a placenta; there is no inflection of the lower jaw; the shoulder-girdle has additional bones; there are no true nipples; the teeth are either absent or horny; the external ear is not present, and there is not a true pouch. The excretion of the kidneys and the contents of the bowels fall into one receptacle, through which the young also pass. It is called a cloaca, and receives the outlets of the rectum and urogenital canal. The presence of the spur on the heel is also a peculiarity.

A fossil Echidna has been discovered in deposits on the Darling Downs.

The Echidnas form one genus and the Ornithorhynchus another, and the classification of the whole is as follows:--

ORDER MARSUPIALIA. SUB-ORDER MONOTREMATA. Genus Echidna. Genus Ornithorhynchus.

In concluding this Natural History of the Marsupiata and Monotremata, it is necessary to direct attention to the fact that they are less well defined than the other great groups of the Mammalia. As sub-orders, they are very artificial, for some of their most important structural peculiarities are deficient in some of the genera. The inflected lower jaw is not invariably found, the marsupium does not always exist, and the marsupial bones differ in shape and size, and are occasionally absent. With regard to these bones or cartilages, they are not connected with the pouch, but with the muscular system of the belly. They have been shown by Huxley to be present in Crocodiles, and in the amphibian called the Salamander. Hence these structures are relics of a remote ancestry, and have but slight functional importance. The authorities whence I have derived most of this Natural History are Waterhouse, Owen, Huxley, Bennett, Gould, and Kreeft, to whom I am under great obligations.

P. MARTIN DUNCAN.

Postscript.--Mr. W. H. Caldwell has discovered that the Monotremes lay eggs as has been suspected, and he has traced the development of the animal during the hatching. The eggs resemble those of a Reptile more than a Mammal, and the yolk is in such excess that it is not all subdivided during the early stages of the embryo of the Monotreme, but some remains over and above, upon which it is nourished in the early stages within the egg. The heart of Ornithorhynchus paradoxus is interesting because Meckel, and, subsequently, Prof. E. Ray Lankester, F.R.S., have shown that it differs from that of the higher Mammalia, and is not without considerable resemblance in some of the valvular structures to the hearts of Birds and Crocodiles. The last-named naturalist states that the reflux of blood into the right auricle on contraction of the ventricle, is not prevented by the presence of the special structure seen in Mammals, but by an arrangement which is observed in Reptiles and Birds. The mitral valve is with three divisions instead of two, as in the higher Mammalia, but the tendinous structures seen in this last group, to terminate the muscular structures, do not exist in the Monotreme. This increase of the muscular structure is not so palpable in Echidna. It is interesting to know that the special structures of the right side of the heart in the adult Ornithorhynchus are seen in the embryonic condition of the higher Mammalia.

THE CLASS AVES.--THE BIRDS.

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I. INTRODUCTION--WING-STRUCTURE AND FEATHERS--DISTRIBUTION

Introduction--Distinctive Characters of the Class Aves--Power of Flight--The Wing--Its Structure--The Six Zoo-geographical Regions of the Earth--Birds peculiar to these Regions.

The study of birds is almost an instinct in an Englishman: from peasant to noble, an innate affection for the feathered songsters seems to prevail; so that whether it be in a stately aviary or in a little cage outside a cottage door, birds are found to be the constant companions of man throughout the length and breadth of the land. And it is possible that no other country in the world possesses such a number of birds, in proportion to its size, as does Great Britain. Any one travelling on the continent of Europe cannot fail to notice how few birds meet his eye; and although they may be there, and may be found by a little searching for, they do not form such a prominent feature of a walk as they do in England or Scotland. Even the toiler in large towns has but to get a little way into the nearest fields to hear the cheering song of the Skylark or the Thrush, or to be amused with the bustling and active habits of the Starling, or those of the more sedate and cautious Rook. It is certain that a study of the habits of birds will always repay the student, who may see in the feathered favourites which are around him many a little bright example to be followed, if he read the lesson aright. Birds teach us many things--perseverance, fidelity, parental affection, thrift, cleanliness, and many other domestic virtues, which are to be seen carried out in their life in the greatest perfection. In the following pages the birds will be passed in review, and the habits of some of the most striking and important forms will be detailed. But, although every species and genus cannot be noticed here, it is necessary to assure the student that in every country--even in England, where so much has been done for Ornithology--he will find an ample reward in the study of all birds; and that even the commonest species cannot be neglected, for there is always something new to learn and to record in their life-history. To quote Dr. A. E. Brehm, one of the most accomplished observers of nature, who, carefully trained by his father, a true naturalist also, has studied the feathered tribes in many climes:--

“He who is only half at home with nature on this earth of ours will be able approximately to appreciate the feelings with which the naturalist wanders and travels from place to place: wherever he may be he finds friendly forms. For years he has silently watched the interior economy and household arrangements of animated nature, and yet he has not seen all; and on this account he is never in want of employment. Every bird is a personal friend: the old ones he knows almost as well as he knows himself, and the new ones must be studied. How much more is there yet to observe! Rich as he may be in experiences, every fresh ramble brings him fresh mental treasure. The relations existing between him and the bird become each day more and more intimate; he knows the lives and habits of each: when each arrives, or takes its departure: where is its abode: how it is made: when it is occupied by a happy troop of nestlings: when deserted. The naturalist knows his friends by their notes, flight, and bearing. In his eye the bird never ceases to exist: alive or dead it is always interesting in his eyes, for in either case the bird is associated with a poesy of feeling in creative nature which he would put into words. Every new bird raises his spirits a step higher; every fresh discovery is a step onward in the knowledge of the ways and means of all things. He is indebted to his friends for many a happy hour; their lives are a pattern worthy of imitation.”[132]

Here, then, we may ask--What is a bird? How can a bird be told from all other Vertebrate animals? The chief character which distinguishes the class of birds is undoubtedly the clothing of the body with feathers. Other characters they also possess, but not exclusively. For instance, they have the power of flight developed in the greatest degree: but there are some birds, such as the Apteryx, the Ostrich, and the Cassowary, which cannot fly at all; while, on the other hand, there are flying mammals, such as Bats, Flying Squirrels, and there are flying reptiles, which can progress through the air by means of flight. Again, birds lay the eggs from which they produce their young; but so do many reptiles and fish: so that this cannot be considered a prerogative of the class of birds. Their bill is hard and sheathed in horn; but so is that of the Duck-billed Platypus (page 231), an animal belonging to the Monotreme Mammals; and Turtles also have beaks. Most, but not all, birds build nests; and in this they stand almost alone among the higher animals; but nest-building propensities are developed in many of the Mammalia--in the Lemurs and Mice, for instance--while it cannot be assigned as a habit peculiar to birds, as the wonderful nests made by some fish conclusively prove.

All birds, whether they fly or not, are clothed with feathers, and this distinguishes the class Aves in the existing state of nature. The majority are specially adapted for flight: and as this is undoubtedly the most vigorous form of locomotion, the greatest muscular efforts being required to raise and sustain a body above the ground and to propel it rapidly through the air, a large development of muscular energy is necessary. The great strain on the circulation of the blood is met by a heart not only as complete as in the Mammalia, but with stronger and a peculiar valvular mechanism for propelling that fluid vigorously through the body. Moreover, in addition to their lungs, birds possess a singular provision of air-receptacles within the body, and these are connected with a series of cavities, also filled with air, which occupy the interior of most of the bones. These cavities serve not only to give lightness to the bird’s body, but they also assist the lungs in aërating the blood, so that birds may be said to enjoy a double respiration. As birds exceed mammals in the activity of their breathing and circulatory system, so also they possess a higher degree of animal heat, their temperature ranging from 106° to 112° Fahr. This high temperature, which exceeds that of the Mammalia by from 8° to 14°, is maintained by its admirable feather-clothing, which, being a non-conductor, effectually serves to guard against any sudden variations of temperature in the air to which its body is exposed, during its rapid and extensive flights, as well as tempering the usual radiation from the body.

As one might expect in the fore-limb of a creature specially organised for suspension in, and progression through, the air, it is found that the muscles, as well as the bones and joints, of the bird’s wing become much modified as compared with the corresponding parts of other animals. With all our scientific knowledge and mechanical contrivances, no one has yet succeeded in constructing a flying machine. It is a significant fact that Nature has not only long ago solved this problem, but that she has done so in several ways. The flight of an insect, of a bird, of a bat, is equally perfect in its way: but in each case the result is attained by very different modifications in the skeletal and muscular apparatus. The principal resistance that a flying animal has to work against is its weight: that is, the force of gravity which, proportionately to its mass, tends to draw it down vertically towards the earth; hence the muscles which are largest and strongest in a bird are those which pull down the wing against the air, thereby raising the body and overcoming its weight.

The chief muscle thus employed is the “great pectoral,” attached to the large keel (or ridge) on the breast-bone, and inserted into the “humerus,” or “arm-bone.” This “great pectoral” is generally the largest muscle in the bird’s body, and in fact often equals in bulk all the other muscles put together.

The wing is opened out by straightening the elbow and the wrist-joints. The former process is effected by the contraction of the triceps; the latter chiefly by the action of the so-called “radial extensors,” and by the elasticity of the long “tensor,” or ligament, which comes from the shoulder muscles along the front border of the anterior wing-membrane, and is attached to the base of the thumb, at the front side of the wrist.

The wing is folded by the bending of the elbow and the adduction of the wrist-joints. The elbow is bent principally by the contraction of the “biceps” and the “internal brachial,” the wrist-joint chiefly by the contraction of the “hand-adductor,” and of the “ulnar wrist-flexor.”

As already stated, the possession of feathers is one of the most characteristic features in a bird. These beautiful structures are modifications of the skin, just as are the scales of the feet and the claws of the toes. Feathers and hairs, scales and claws, are all produced out of, and are modifications of, the cells of the upper skin, or epidermis, and of the under, or true skin, or cutis. The feathers differ much in their minute construction in some birds; and all those of a bird are of course not of the same size and shape, but they have the following parts in common.

A feather consists of a quill, a shaft, barbs, and barbules: moreover, there may be a kind of accessory part, often in the shape of a downy tuft, close to the junction of the shaft and the quill. The shaft (scapus) or axis of every perfect feather (penna) is divided into the quill (calamus), the hollow cylinder (d), which is partly embedded in a sac of the skin, and the true shaft (rachis, a), which bears on each side the lateral processes called barbs (rami or radii). The rachis and the barbs together are known as the vane (vexillum), and, in fact, form what is commonly known as the “feather” in contradistinction to the “quill.” The barbs (c, c, c, c) are narrow plates, or laminæ, “tapering to points at their free ends, and attached by their bases on each side of the rachis. The edges of these barbs are directed upwards and downwards, when the vexillum of the feather is horizontal The interstices between the barbs are filled up by the barbules, pointed processes, which stand in the same relation to the barbs as the barbs do to the rachis. The barbules themselves may be laterally serrated and terminated by little hooks, which interlock with the hooks of the opposed barbules. In very many birds each quill bears two vexilla; the second, called the aftershaft (b) (hyporachis), being attached on the under side of the first,”[133] close to the junction of the shaft with the quills.

In all the feathers of the Ratitæ, and in the case of all but the contour feathers in other birds, there are no barbules to the barbs. The pennæ are ordinarily arranged in definite patches, or areas on the bird, and the shape and size of these, and their relation to one another, differ in many birds.

The aftershaft (b) is ordinarily a smaller vexillum, which is attached to the under side of the larger one at about the point where the rounded quill passes into the stem.

It is not necessary to notice these important characteristic structures more fully now, as they will have to be considered in explaining the distinctions between the great groups of birds, and we pass on to notice that the same kinds of birds are not found everywhere, but that they have, as groups, a remarkable geographical distribution.

In the following pages the distribution of birds is often alluded to, although it will naturally be impossible to discuss, within these limits, all the various phases of the study which the geographical distribution of the feathered tribes opens up to us. At the same time sufficient evidence will be given to show that birds are not scattered without order over the earth, but are more or less restricted to certain spots.

The six natural history or distributional provinces into which the world is ordinarily divided by modern naturalists were determined, first of all, from the study of the birds; and in fixing the boundaries of each division the wading birds and many swimming birds must be left out of the question, as they are creatures of such very extensive flight, and wander almost from pole to pole. A natural region, therefore, can be marked only by its resident forms of bird life, or at the most by the birds which breed within its limits; and the six regions alluded to provide us with many excellent reasons for believing that they possess well-defined physical boundaries. No Capercailzie, for instance, was ever found out of the Palæarctic[134] region, which comprises Europe and the greater part of Asia above the line of the Himalayas and the Yangtze-kiang River in China. This region is also characterised by a large number of Buntings, Warblers, Grouse, &c. In the Nearctic[135] region there is a certain similarity to the European and Siberian Avifauna, Grouse, Ptarmigan, Waxwings, Magpies, Ravens, &c., being commonly found throughout the two regions. North America possesses, however, several forms peculiar to itself, though it is by no means so rich in species as is the Neotropical[136] region, which commences south of a line drawn through Northern Mexico, and includes the whole of Central and Southern America. Within this large area are contained whole families of birds, such as Toucans, Mot-mots, the vast majority of the Humming-birds, Trogons, besides innumerable genera of Tanagers and other forms, so that this region is by far the richest in the world as regards bird life. The Ethiopian region embraces all Africa below the Sahara Desert and Madagascar: Plaintain-eaters, &c., are characteristic of this region. The Indian region skirts the Palæarctic, and includes the remainder of Asia below the Himalayas and the Yangtze-kiang; the Malayan Peninsula, the Sunda Islands, and the Philippines, belong to this region, which contains all the finest Pheasants in the world, the Impeyan Pheasant from the Himalayas, the Tragopans, and the Lobed Pheasant of Borneo being most beautiful creatures. Lastly, between the islands of Bali and Lombok passes a deep sea boundary called “Wallace’s line,” which divides the Australian region from the Indian, and although these islands lie so close together, the great depth of the channel between them seems to mark them out as frontier lines of two ancient continents. Certain it is that the birds and animals on each side of Wallace’s line differ remarkably; and the Australian region, which includes all the Moluccas, New Guinea, and Oceania, in addition to the Australian continent and New Zealand, presents us with forms not found elsewhere, such as Birds of Paradise, Cassowaries, Lyre-birds, and a large variety of peculiar types. Many smaller divisions of the globe are now recognised, but the above are the main ones, which may occasionally be referred to in these pages.[137]

Many birds migrate, and the student of migration alone would find sufficient material there for the work of a lifetime; and it seems almost impossible to account for the instinct or other causes which bring birds regularly year by year to breed in the same haunts, and which drive them away at the same change of season. Why is it, for instance, that species of similar habits and form, and both visiting Europe in equal abundance, should occupy such different winter quarters? Yet the common Red-backed Shrike, or Butcher-bird (Lanius collyrio), when he is said to leave Europe, passes by the Nile Valley along the east coast of Africa down to the Cape, where he brings up a second brood of nestlings; while the Wood-Chat Shrike (Lanius auriculatus), a bird of about the same size and of precisely similar habits, proceeds down the Nile Valley and invades Abyssinia in the winter, and also occupies Senegambia, where a Red-backed Shrike has never been found yet by a naturalist. Nothing whatever is known by which route the bird gets to the Gambia: whether he follows the same one as his red-backed relation as far as Abyssinia, and then skirts the southern edge of the Sahara, or whether he reaches north-western Africa by a direct flight across the Great Desert. Many other such problems in the economy of our most familiar species are still awaiting further scientific research.

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II. THE ANATOMY OF A BIRD.[138]

The Three Divisions of the Class Aves--ANATOMY OF A BIRD--The Skeleton--Distinctive Features--Peculiar Bone Character--The Skull--Difference between the Skull of Birds and that of Mammals--The Jawbones--Vertebral Column--Sternum--Fore-limbs--Hind-limbs--Toes--The Muscular System--How a Bird remains Fixed when Asleep--The Oil-gland--The Nervous System--The Brain--The Eye--The Ear--The Digestive System--The Dental papillæ--The Beak--Tongue--Gullet--Crop--Stomach--Uses of the Gizzard--Intestine--The Liver, Pancreas, and Spleen--The Blood and Circulatory System--Temperature of Blood of a Bird--Blood Corpuscles--The Heart--The Respiratory System--Lungs--Air-sacs--The Organs of Voice--The Egg--Classification of the Class Aves.

Birds may be separated into three great divisions: the Carinatæ, or birds with a keeled sternum, the Ratitæ, or birds having a raft-like sternum, and the Saururæ, or lizard-like birds. The last of these orders links the birds with the reptiles, and does not concern us here, as it contains only one genus, and that a fossil one, the Archæopteryx lithographica, respecting which a few words will be found at the end of this article (Vol. IV., pp. 236-8). The other two divisions are of great importance, and are easily recognisable, although the characters which separate them are chiefly anatomical. The principal point of difference lies in the sternum, or breast-bone, and the name Carinatæ is given to all those which have a keel (carina) or sternal ridge largely developed, as in the common fowl; and this is present in the great majority of birds. The Ratitæ have not got this keel, and in this division are found the Struthious birds--Ostriches, Cassowaries, &c. They are all species which cannot fly; and although the number at present existing is small, the fact of their being found at widely distant parts of the earth--in South America, in Africa, and again in Australia--would seem to indicate that they were once more plentifully distributed, and that they are remains of what was formerly a large and important group. To these Ratite birds belonged also the extinct gigantic Moas of New Zealand, and the Æpyornis of Madagascar.

Before proceeding further, it will be necessary to give a brief outline of the principal anatomical features of a bird’s body. On examining either the general features of the skeleton, or the minute characters of many of the bones of which it is made up, in such a bird as a Hawk, for example, we are arrested by those remarkable arrangements by which this part of the body is adapted to the mode of life of its possessor. Here, however, as in so many instances, we have to distinguish between what is characteristic of the bird as a flying animal, and what is more or less common to it and other vertebrate animals, and does not especially relate to peculiar habits. We may well be struck by the marvellous power which birds have, and which man has not, and it is curious to notice how man’s aspirations have ever been associated with it. Without pausing to observe that painters always endow spirits with wings, or that the imaginative genius of the French has emboldened them to form a “Société d’Encouragement pour la Locomotion Aérienne,” we may find in the words of Faust definite expression of what man feels with regard to the law by which he is held down to earth:--

“Ich eile fort, ihr ew’ges Licht zu trinken, Vor mir den Tag und hinter mir die Nacht, Den Himmel über mir, und unter mir die Wellen. Ein schöner Traum, indessen sie entweicht. Ach! zu des Geistes Flügeln wird so leicht Kein körperlicher Flügel sich gesellen. Doch ist es jedem eingeboren, Dass sein Gefühl hinauf und vorwärts dringt, Wenn über uns, im blauen Raum verloren, Ihr schmetternd Lied die Lerche singt, Wenn über schroffen Fichtenhöhen Der Adler ausgebreitet schwebt, Und über Flächen, über Seen Der Kranich nach der Heimat strebt.”[139]

Inspired by feelings such as those so powerfully expressed in Goethe’s lines, numerous naturalists have treated of the bird as though the powers of flight were confined to it, and were not shared by Bees and Bats in the present, and by Pterodactyles in the past. With this word of comment, which it is even still necessary to insist upon, attention should be given to the following avian characters:--The anterior limbs do not touch the ground, and the bones which compose them are adapted for carrying the feathers of the wing; the breast-bone is not only elongated, but has its central portion developed (except in the Ratitæ) into a strong keel, the better to permit insertion of the muscles by which the fore-limb is moved; the small bones (vertebræ) in the region of the back are fixed firmly together, and are not, as in man or in the Ostrich, movable on one another; while those which succeed them are often welded into one mass with the greatly-developed upper bones (ilia) of the pelvic girdle; and the hinder vertebræ develop an upstanding plate (ploughshare bone) which gives support to the rectrices, or so-called steering feathers of the tail. It will have been seen that the ordinary seizing organ of man (the hand) has in birds been modified to serve another purpose; but this is made up for, not only by the character of the beak, but by the long and flexible neck, and in some by the grasping toes.

Before describing in detail the characters of the different parts of the skeleton, it is to be noted that many of the bones are not, as in the Mammalia, filled with marrow, but with air; a large cavity may, for example, be seen in the upper bone (humerus) of the wing of the common fowl. It is obvious that the specific gravity, or weight of the bird, is thus largely reduced, while the connection between these air-spaces and those which are derived from the lungs enables the contained air to undergo the necessary exchanges with the surrounding medium.

It was long ago observed by the famous German anatomist, Johannes Müller, that “it has often been a subject for complaint that the anatomical characters of birds are so constant that they are of but slight assistance in the labours of the zoologist.” The truth of this will very forcibly strike any one who comes to the study of the skulls of birds, after having examined a series of skulls in mammals, so that the seemingly trivial variations to which anatomists have directed attention are in truth those which are, in birds, often of the most importance.

The skull, then, is, as compared with the rest of the body, small; but that portion which contains the brain is relatively larger to the face than it is in any living mammal. The orbits, or cavities in which lie the eyes, are very deep, in consequence of the small extent to which the walls of the brain-case extend forwards. The cavities of each side are separated by a partition (inter-orbital septum), which is more or less bony; the nasal bones are short, so that the nasal orifices (anterior nares) are placed near to where the beak joins the face. Of the four bones which bound the great opening at the back of the skull for the passage of the spinal cord, three take part in the formation of the single ball-like projection, or condyle, by which the skull is hinged on the vertebral column. In this point, the skull of birds offers a striking point of dissimilarity to that of mammals, in which there are two condyles, one on each side of the great opening (of). Another point in which birds do not resemble mammals is in the mode by which the lower jaw is hinged on the skull. This is in the case of birds effected by a bone, which, being more or less square in shape, has gained the name of the quadrate (q). In mammals the skull proper and the lower jaw are directly connected. This quadrate bone is connected by a long narrow bar (quadrato-jugal) with the bones which go to form the “beak,” and also, by a narrow bone directed inwards, with the bones which lie in the middle line of the base of the skull, and form the hard palate. The connections between these bones are often of such a kind as to allow of the upper jaw, or upper half of the beak, being movable on the rest of the skull, the upper bones of which are so completely united together as to form a very firm point of support. In the Parrots this arrangement is carried to an extreme, for the slender bones (nasals and processes of the pre-maxillaries) which connect the upper jaw with the bones of the brain-case form with them a distinct joint, and so allow of that large amount of vertical movement which will have been observed in these birds. The pre-maxillary bones (pm), which are so small in mammals, are very largely developed in birds, giving off, as they do, three processes: one to the frontal bone (or fore-bone of the brain-case), one along the hard palate, and another externally to form the margin of the beak. The parts that vary most in this bone-group are the bones which make up the hard palate. Of these, the chief are the so-called palatines (p) and the maxillaries; the former are united by an articular surface with the bone which forms the anterior part of the base of the brain-case, while there is in the middle a narrow bone, which, from its shape in man, has received the name of the vomer (ploughshare, v). The maxillary bones develop horizontal plates, which have the palate below and the nasal chamber above them.[140]

The lower jaw (ma) is composed of six pieces of bone on each side--the dentary, angular, surangular, coronoid, splenial, and articular. The upper part of the joint is concave.

The tongue is in relation, as regards its support and movements, to the hyoid bones, which will be especially noticed in describing the Woodpecker.

Turning to the vertebral column, we find a number of small bones, complicated in form, and more or less movable on one another. For convenience of description they may be divided into those which belong to the neck (cervical vertebræ), to the trunk (dorsal vertebræ), to the sacrum (so-called because it was offered in sacrifices!), or to the tail (caudal vertebræ). As has been observed already, the first of these, or the region of the neck, is very long, and is always long enough for the beak to be able to reach to the base of the tail. In birds, unlike mammals, the number of these cervical vertebræ may be as low as nine, or as high as twenty-four. The first of them, which is known as the atlas, has on its front face a rounded cavity into which fits the single projecting condyle, which was spoken of as being found at the back of the skull; and this condyle, being well rounded, is easily able to turn in the cavity which it fits, and the head is thereby capable of a large amount of movement. In the succeeding vertebræ it is possible to make out a body, an upper arch, through which passes the spinal cord, which meets above in the middle line, and is produced into a more or less long spinous process set horizontally to the “body,” and others directed forwards and backwards, so as to connect each vertebra with its neighbours; and lastly, a lower arch, the two halves of which are not connected below, but are converted into the more or less long ribs. As these vertebræ are so small it is clear that if their spines were long the free movement of the neck would be greatly impeded, and they are therefore in many cases little more than projecting processes. This free movement is further greatly aided by the characters of the two faces of the body (or centrum) of each vertebra; the face of each is saddle-shaped, that is to say, the anterior face is concave from side to side, and convex from above downwards, while the reverse of this is seen on the posterior face; in addition to this the vertebræ are separated by a disc of cartilage from one another. The region of the neck is, broadly speaking, distinguished from that which succeeds it by the fact that the ribs connected with its vertebræ do not reach to the sternum, or breast-bone. In all birds which are capable of flight this dorsal region has its parts firmly united together, and the same holds for the parts which follow, till we reach the region of the tail, where the more anterior vertebræ are movable on one another, so as, perhaps, to serve in aid of the steering organ formed by the rectrices, or feathers (co). In all living birds the caudal vertebræ are a good deal shorter than the body, but in the fossil Archæopteryx they are longer.

The only important point to note with regard to the ribs, is the presence on some of them of backwardly directed hooked processes (up, fig. on p. 241), which aid in giving firmness to the thoracic region. The number of ribs is variable, but there is never a large number connected with the dorsal vertebræ, as there are in some Carnivora, in Hyrax, and in the Horse.

The fore and hind limbs are connected to the body by a series of bones, which form the breast and hip girdles respectively; with the former series is also connected that large, long bone with its sharply-projecting ridge (is), which is known as the breast-bone, or sternum, and in the depressions on which so much muscle is collected. This sharply-projecting ridge to the sternum, which is known as the carina, or “keel” (cs), is found only in the flying birds, though here and there, as in the Parrot of New Zealand (Strigops), it is very rudimentary. The lower edge of the bone is often imperfect, so that, as in the fowl, there are two deep clefts on each side, or there may be but a single cleft, and this again may be converted into a rounded space; in all cases these clefts or holes are covered, or filled by membrane, during the life of the animal. Projecting in front of the sternum, and often intimately connected with it, are the two clavicles (cl), which unite in the middle line to form the bone of childhood’s delight--the furcula, or “merrythought.” Above, this bone is connected with two bones, one of which, called the coracoid (c), descends on each side to fit into a depression on the upper edge of the sternum, while the other, known as the scapula, or shoulder-blade (sc), is set at an angle to the coracoid. The scapula has a backward and downward direction; while it may be noted that among mammals the coracoid is well developed only in Echidna and Ornithorhynchus. These two last bones form, at their point of junction, a cavity into which is fitted the head of the long bone of the arm (wing). In the Ratitæ, it must be observed, these two bones are not set at an angle to one another, and they become more firmly united together.

As in all the vertebrate animals except fishes, the fore-limb may be divided into three parts (fig. on p. 237)--upper arm, in which there is one bone, the humerus (a); fore arm, in which there are two, radius (d) and ulna (c); and hand (E), which can again be divided into three parts, which in man would be called wrist, palm, and fingers. Now, in some animals the wrist-bones may be ten in number, and the palm-bones five, while the number of small bones in the fingers varies a good deal, but the number of fingers is five. In most birds all these numbers are reduced. Just beyond the fore arm, the larger bone of which has often small projections indicating the points at which the secondary feathers have been attached, there are two small bones (f), then comes a longer bone (g h i), as it seems, in which there is an elongated space. Now, this bone consists of three metacarpals and one wrist-bone; the two outer metacarpals are absent, the two innermost ones have completely united with one another, and with the (true) middle metacarpal bone at their upper end; while the second and third metacarpals are also united at the other--or finger--end. The inner digit (k), or that which corresponds to man’s thumb, has two joints (phalanges), and may be clawed; the next has three joints, and may also be clawed; while the third finger, which has never more than two joints, is never known to carry a claw. In the Archæopteryx the metacarpal bones are well developed, and are not, as in recent birds, united together. No idea of a bird’s flying powers can be fairly gathered from the length of the hand, for it is long in Swifts and short in Albatrosses, for example; although it is to be noted that in the former the single bone (humerus) of the arm is short, and in the latter long.

As in the breast-girdle, the bones of the hinder or hip-girdle, by which the hind-limbs are connected with the body, are three in number; of these the upper one is greatly flattened out and projects very far forwards, thus aiding in the formation of the firm back of flying birds; the other two bones are much more slender, and are directed backwards and downwards. It is a curious circumstance that it is in one bird only, in either case, that these bones are directly connected at their lower ends with their fellow on the opposite side; those which are known as the pubes (pb) are so in the African Ostrich, and those which are known as the ischia (is) in the Rhea of South America. These two bones, with the large, flat ilia (il), take part in forming the cavity in which the head of the thigh-bone plays; the outer of the two bones (fi) which are found in the leg is rarely as long as, and is always much more slender than the other (ti), which has a strong ridge on its front face. There is yet another very remarkable point of resemblance between birds and reptiles, in that the “ankle-joint” is in both cases situated between the two rows of bones which make up the “ankle” (tarsus). In birds this arrangement is carried to a still further extent, for the single bone of the upper row is early united with the shin-bone, as may be seen under those unfortunate circumstances in which the poulterer has provided an aged fowl (aged, that is, for eating); in more fortunate cases it will be found possible to separate a small bone from the lower end of the shin-bone of the leg.

In no case does any bird, even Archæopteryx, possess a fifth toe. Unlike mammals, the number of joints in the toes varies greatly in birds. In those which possess four toes we find the following number of joints: in the first, two; in the second, three; in the third, four; and in the fourth, five. This rule holds for nearly all birds, but the Swifts have never more than three joints, and in the Goat-sucker and the Sand Grouse there are two less than ordinary on the fourth toe. In a number of birds the inner toe (big toe of man) disappears, and in the Ostrich proper the next division of the “typically” five-toed foot, or second toe, has no toe-joints.

In dealing with the muscular system of birds, we need here concern ourselves with only those special muscles which are modified in accordance with the necessities of the bird’s habits, and those other muscles which have been brought into special notice by valuable investigations.

That great fleshy mass which is found on the breast of a bird, and which is not unknown to those who are fond of a good “dish,” consists of three separate muscles, two of which depress, while the other elevates the wing. The presence of the elevator muscle on the lower side of the sternum is a curious arrangement by which the centre of gravity of the animal is lowered--a most necessary condition in flight; the tendon from this muscle passes through a pulley-like canal to be inserted into the upper side of the head of the bone, which, as has already been explained, is known as the humerus, so that when it contracts it draws this bone up. The ability of the wings to resist the pressure of the air is clearly dependent on the power possessed by these muscles. Borelli has calculated that the “pectoral muscles” of the bird exceed in weight all the other muscles taken together, whilst in man the pectoral muscles are but a seventieth part of the mass of the muscles.

The large and important muscles, which in the Mammalia, constitute the diaphragm, or midriff, are ordinarily said to be absent in birds, and, indeed, in most cases are but feebly represented. In the Ratitæ, and especially in the New Zealand form (Apteryx) of this group, the diaphragm may attain to a very fair degree of completeness, though even here the apex of the heart is allowed to pass into the abdominal cavity. The muscles of the back are feebly developed, as might be imagined from the firm character of the spinal column; and as the fore limb exhibits but slight power of varying its movements, its muscles are not well developed. Those muscles which are found in the skin are, on the contrary, expanded into broad pieces; and special bundles are sent to the larger feathers of the wings and of the tail, and to those folds of skin which connect the upper arm with the trunk, and with the fore arm, respectively. Borelli thus explains the arrangement by which a perching bird remains fixed when asleep: A muscle which arises from the pubes bone of the hip-girdle passes over the knee, and then takes a backward direction so as to pass behind the ankle; it thus becomes one of the flexor muscles, by the contraction of which the toes are flexed, or bent. When the perching bird, which, as we know, has one of its toes directed backwards, is seated on a bough, the thigh has its upper end directed backwards, while the upper joint of the leg is turned forwards, or in other words, the two parts of the leg have opposite directions. This arrangement acts as a contracting influence on this muscle and its tendons, while the weight of the bird is sufficient to preserve this condition and the consequent flexion of the toes.

To turn to those muscles the arrangement of which has, been made the basis of a suggested classification. In the leg of the bird there are, among others, four muscles, the names of which are femoro-caudal, accessory femoro-caudal, semi-tendinosus, and accessory semi-tendinosus, any of which may be absent, but in those cases where a single muscle only is found the first is always present; again, there is a muscle which, from its course, is known as the ambiens, and this, too, may be present or may be absent. As the presence or absence of any of these muscles is a very constant phenomenon in any given section of birds, it has been proposed to divide the class into those which do, and those which do not, possess the above-named ambiens muscle. In the latter group the second of the four above-named muscles--the accessory femoro-caudal--is never present.[141]

Of all the muscles, those which act in aid of the vocal organs are of the greatest interest, but they will be considered a little later on.

A valuable suggestion has been made, which, if followed out, may lead us to understand how it is that the brain of the bird, which is so simple as compared with that of man, is nevertheless capable of so much intelligent activity. Bearing in mind the axiom that it is quality not quantity that tells, and looking at the fact that the brain of the most highly intelligent man is, after death, supposed to be similar to that of the foolish and of the unwise of our race, it is obvious that the essential difference must lie elsewhere than in the coarser, or more evident, characters of that organ which is known as the brain. The suggestion, then, that was made, was to the effect, that the possessors of aviaries, in which it was possible to study the characters of birds, should submit the brains of their deceased favourites to that more thorough investigation which the microscope allows of. The brains of birds vary but little in their anatomy. The optic lobes are rounded, paired, and tubercular in the bird, and are not divided into four, as in mammals; they are found at the lower part and sides, and not in the upper part of the brain. The cerebellum is not continued at the sides into distinct lobes; nor are the two lobes of the brain (or cerebral hemispheres) provided with those convolutions which, in mammals, seem to increase in complexity of character as the animal rises in the scale of intelligence. The cerebrum does not cover the cerebellum. Small as is the brain of birds, it is found that, in many, its weight is, as compared with that of the body, much greater than it is in man.

With reference to the spinal cord, or the continuation of the central part of the nervous system through the vertebral column, it is only necessary to remark that it is much increased in width at the two regions, in which the nerves for the fore and hind limbs are respectively given off; that there is a narrow canal running along its centre, and that at the lower end there is a large space. In regard to the cerebral nerves, those for the eyes are of great size.

Coming now to consider the organs of the senses, and beginning with the eye, it is interesting to note that there are no blind birds, and, indeed, the eyes are of a large size as compared with the brain. They are generally placed at the sides, though the nocturnal birds of prey (in which they are directed forwards) are an exception to this rule. It is in very rare cases that eyelashes are present, and although they seem to exist in the group just mentioned, it is probably more correct to look upon them as slightly modified feathers.

If the eye be regarded as having on its front face, a part which would, if completed, form part of a smaller circle than the rest of the eye, it is clear that this cornea, or front part, would be more convex than the rest, and that it would consequently be a “more powerful glass,” inasmuch as it would exert a greater bending (refracting) influence on the rays of light which pass through it, while, further, it is clear that the more convex it is the better “glass” would it be. Now this is just what happens in birds: the cornea is very convex; in addition to this, the long axis of the eye, on the length of which it seems that, in many cases, the condition known as that of being “short-sighted” depends, is very long in some birds, and notably in the Owls.

The eye is covered in by a firm and strong membrane, which is known as the “sclerotic;” this, in its front part, develops a number of bony plates; of these there may be as many as twenty, and they are capable of a certain amount of free movement on one another. What is known as the power of accommodation depends upon the extent to which the front face of the somewhat lens-shaped body which helps to separate the eye into two chambers is capable of being rendered more or less flat; this front face is covered by a membrane which is found to be more or less taut, according to the state of contraction of the muscles (ciliary muscles) connected with it. A very little reflection is sufficient to show that a swiftly moving animal has the focus of its eye, or the point at which clear vision is alone possible, changed much more rapidly than an animal which moves more slowly. So much on the one side. On the other, it is to be observed that muscles vary in structure; they are either “smooth” or “striated,” and it is the latter that contract the more rapidly. Putting these two series of observations together, it is easy to arrive at the result that a bird should have striated muscular fibre in its ciliary muscles, and a more slowly moving animal like man, smooth muscular fibres; and this we find to be the case! The iris is an arrangement by which the quantity of light admitted into the eye is enabled to be varied, and the small hole in the centre, through which the rays of light pass, is known as the pupil; this is always rounded in birds, and is never elongated as it is in some mammals--the Cats, for example.[142]

But the most peculiar arrangement in the bird’s eye is the presence, projecting into the hinder chamber, of a membrane in which run blood-vessels; this, which is known as the pecten (comb), or marsupium (pouch), enters the vitreous humour, which fills up this hinder chamber by the same cleft as the optic nerve. It is folded, and is generally of a quadrangular shape; it is not found in the eye of the Wingless Bird of New Zealand (Apteryx).

A third eyelid is well developed in this class; it is an elastic membrane (membrana nictitans, or winking membrane), which has not, like the other two, a vertical movement, but is drawn obliquely over the eye from the inner to the outer side. This movement is effected by two special muscles, one of which arises on the inside, and below the eyeball, and has therefore to pass over to the outer side. In contracting, it would press on the optic nerve, were it not for the other one, which, however, is so disposed that by its contraction it draws away the tendon of the pyramidalis muscle from pressing on the nerve. As in ourselves, there are six special muscles for moving the orbit or ball of the eye, but the one which in man is well enough known as the trochlear, has no pulley-arrangements in birds. Lachrymal glands are present.

With regard to the organ of hearing, one particular part, which in man is in the form of a snail’s shell, and is known as the cochlea, is not coiled into this shape in birds, being very slightly bent, though holding in other respects the same general relations. Nor is there any external ear, as in mammals, for collecting the waves of sound; there is, however, in the nocturnal birds of prey a crescent-shaped valve on which are set tufts of short feathers, and it is possible that this may aid in hearing. Nor, again, are there in the interior of the ear those three small bones, which are known generally as the auditory ossicles; of the two that are absent, one is thought by many anatomists to be represented by the quadrate bone, which, as has already been mentioned, connects the lower jaw of the bird with the skull. The single bone which is present, and which is, perhaps, most generally known as the “columella,” is connected by two or three cartilaginous processes with the drum of the ear, and by the other end--at which it has a small oval plate--with the more internal parts of the organ of hearing. In man there is a curious arrangement of rods, which vary in so remarkable a way as to have led to the supposition that each was adapted to a distinct note; these rods, which constitute the organ of Corti, are not present in birds, affording thereby a striking example of the law that physiological inferences are often well examined by the aid of comparative anatomy, no physiologist being hardy enough to deny to birds the power of appreciating those delicate modulations of sound which go to make up the chief charm of music. With regard to the organ of smell, it is only necessary to note the absence of those muscles by which, in man and other mammals, the nostrils are contracted or dilated.

The first point which attracts us on examining the digestive tract of birds is the absence of lips and of teeth; but with regard to these latter we must note that it is a character which has only become distinct since the time when birds were first developed. This statement is borne out by two series of facts, each taken from one of the two great aids to a correct apprehension of the real importance of structural characters--that is, from embryology, or the study of the developing individual; and from palæontology, or the natural history of the past. The young of certain Parrots have been observed to possess, at an early stage of their development, those uprisings on the mucous membrane of the jaw which go by the name of “dental papillæ,” and these papillæ have been seen to be covered with a cap of dentine. On the other hand, the researches of Owen and of some American palæontologists have brought to light bird-like forms which were provided with teeth (Odontornithes: Ichthyornis, Hesperornis).

The beak, or horny covering of the jaws, varies very greatly in form, and in the degree of its sensibility. This tactile sense is dependent on the extent to which the beak is supplied by nerves (from the fifth cerebral nerve). In the Woodpecker, for example, there is a large branch extending along the inside of the lower jaw, which, as it approaches the extremity, breaks up into finer nerves that perforate the bone by a number of small canals and so give to the beak a power of discovering what lies hid in the crevices of the wood and under the bark. Being an external structure, the beak is naturally adapted to the habits of its possessors, so that it may be hooked, as in many flesh-eating forms, or trenchant, and fit to cut and break, or provided with transversely-set fine plates by which the water taken in with the food can be filtered off, or provided with bristles, the better to hold a living prey. Finally, in many cases the hardness of the bill is made up for by a patch of naked skin at the base of the upper mandibles, which is known by the name of the “cere” and seems to have a tactile function.

In many birds, the tongue is either feebly developed, or is encased in horn, so that it can hardly be as useful an organ of taste as is our tongue: in the Pelicans it is obsolete. In some, however, as in the Woodpecker, the tongue is a very powerful seizing organ, as it is protruded with great rapidity by means of a special muscle, and is well provided with a sticky secretion, which is given off from a large gland (the sub-lingual), which, lying below the muscle above referred to, is compressed when this muscle contracts; so that in the Woodpecker, just as in the mammal called the Great Ant-eater (Myrmecophaga), the insect prey is easily captured.

The region of the mouth is not separated from that which follows it (the pharynx) by an epiglottis, which in ourselves protects the entrance into the air-passages, nor is there any uvula to guard the posterior orifice of the nose by which the air reaches the throat. The succeeding portion of the gullet (the œsophagus) is very long, as might be supposed from the length of the neck in most birds, and it is very frequently either dilated at one side, or produced into a cæcal pouch (crop, ingluvies), which may, or may not, be separated by a narrow connection, from the rest of the gullet, and which may be divided into two compartments. This crop serves for the detention of the food, which cannot have undergone any complete process of mastication, and it is here treated to a process of maceration by the fluid secreted from the walls of this organ. Passing from this receptacle, the food becomes subject to the action of the stomach proper, which differs, however, from our ordinary conception of a stomach, as seen in man, by being divided into two distinct portions. The anterior one is known as the proventriculus, and it is in this that the gastric juice is brought to bear upon the food, and its walls are consequently thickened by a glandular layer; the hinder division, which is known as the gizzard, forms an elongated sac, with two orifices--one from the proventriculus, the other leading to the small intestine--in its upper portion. The characters of its walls are very different in those birds which live on animal, as compared with those that live on vegetable (grains) food; in the former they are membranous and thin, but in the latter they are enormously thick and very muscular. On examination, it is seen that the dark colour of the muscles is on each side of the gizzard relieved by a shining spot of tendinous material, and the walls of the gizzard have consequently been compared to a double-bellied (digastric) muscle. The internal cavity of the gizzard is lined with a dense and rough coat, and is ordinarily found to contain small stones, and occasionally other hard materials. These obviously take the place of the absent teeth, when the muscles of the gizzard set up that (grinding or compressing) action by which the ingested seeds are broken down. The wall of the gizzard may itself also act as a rasping organ, being, as it often is, provided with a firm glandular layer, the secretion of which is converted into a hard lining, the structure of which has been observed in some cases to be due to interlaced filaments secreted from and continuous with the glands in the wall of the gizzard.

Notwithstanding the differences in the character of the gizzard in carnivorous and graminivorous birds, it has been shown by the ever-famous John Hunter that carnivorous birds can be brought to live on grains, and grain-eating birds on meat.

It is interesting, further, to note, with regard to the opening into the small intestine, that in a number of grain-or fruit-eating birds there is no valvular arrangement to detain the food in the gizzard till it is completely triturated, for it is thus that many plants have their area of distribution increased, the escaped seeds passing uninjured from the intestine to find, perhaps, a suitable soil in a new district. In those that swallow large stones a valve is often to be observed. The difference which we have already had so frequently to notice, as obtaining between the carnivorous and “vegetarian” birds, is seen to be continued into their small intestine; just as in mammals, this portion of the tract is longer in the latter than in the former birds. The anterior, or duodenal portion, is always characterised by forming a loop, within which lies the gland known as the pancreas, and the succeeding portion is, as compared with most mammals, short. A slight elevation, hardly ever of any great size, may at times be observed on the course of the short intestine. This represents all that remains of the duct by which the hatching bird was connected with the yolk. The short and straight large intestine is ordinarily separated from the preceding by a cæcum; this is generally paired (in the Herons and some others it is single), and varies in length; in many cases these cæcal tubes are hardly more than papillæ. In the Parrot, as in the Woodpecker and some others, these cæca are absent. In the desert-dwelling Ostrich (Struthio) they are said to be as much as two feet long; but in the Emu they do not exceed six inches in length.

The intestine ends in a cavity, which is common to it, and to the other organs that open to the exterior in this region. This cloaca (sewer) is found in reptiles also, and in one division of the Mammalia, the Monotremata. In birds it is provided with a special glandular appendage on its upper (or dorsal) aspect, which goes by the name of the Bursa Fabricii. Neither the history nor the functions of this peculiar organ can be said to be thoroughly understood.

Of the organs which are appended to the intestine, the lungs will be described elsewhere; of the rest we have to consider the liver, the pancreas, and the spleen. The first-named organ is large, and covers over the pancreas, the proventriculus, the spleen, part of the gizzard, and part of the small intestine. It is ordinarily divided into two “lobes,” between which, on the upper edge, is placed the tip of the heart. In the common fowl the left lobe is often divided into two; but this organ is never broken up into so large a number of parts as it is in many mammals, from which animals birds also differ in always having more than one duct to carry off the secretion of the liver (bile) to the small intestine, except in the Ostrich; in this, as in some other birds, there is no gall-bladder in which the bile may be collected, so that in such this secretion passes directly into the intestine.

As has been already pointed out, the commencement of the small intestine forms a loop, in which is set the organ known as pancreas, which may for simplicity be described as the salivary gland of this region, although in truth the fluid secreted from it is a much more powerful aid to the digestion of food than that of any known salivary gland. It has always two, and in a number of cases three ducts, which do not unite with the bile ducts, but open separately from, though near them, into the end of the “duodenal loop.” The spleen, which is a small oval body, and is placed to the right of the proventriculus, has no ducts; in birds of prey it is more cylindrical in shape.

The temperature of the blood of the bird is, in requirement with the conditions of its existence, hot--that is to say, it is ordinarily hotter than the temperature of the surrounding air, and is found to register between 100° (Gull) and 112° (Swallow) on Fahrenheit’s scale, or from two to fourteen degrees more than does that of man. Birds and mammals, are, speaking broadly, the only hot-blooded animals now existing, and it has consequently been suggested that they should be grouped together as such, in opposition to the rest of the Vertebrata. But it is obvious that this character of the temperature is merely dependent on physiological conditions; and were this a treatise on the anatomy of birds rather than one on their natural history, the statement of this fact would not receive the prominence here given to it. The high temperature of any body may be preserved from cooling influences by two methods: thus, tea in a well-polished silver teapot keeps hot because the rays of heat are but slightly radiated from its surface; or a less costly teapot may be kept hot by covering it with a loosely-fitting “cosy,” which, being made of badly-conducting materials, “keeps the heat in.” It is, then, clear that the heat of a body is best preserved when it is covered by a bad radiator and a bad conductor of heat; and this is just the case with birds: the polished feathers are bad radiators, and the air entangled among them forms a bad conductor.

The blood corpuscles are, broadly speaking, about twice as large as in man; those which are coloured red are oval in shape, as they are in nearly all of the lower Vertebrates and in the Camels among mammals. Like the white ones, they are “nucleated.” The heart is, as in mammals, divided into four chambers. It is a condition of the circulation in hot-blooded and rapidly-breathing animals that the current of arterial blood from the heart, and the current of venous blood to it, should be kept as much as possible separate; no reflection is needed to show that the blood freshly purified by contact with the air in the lungs must be kept as distinct as can be from the blood which has lost its purity in passing through the body; in other words, it is required that there should be a similar result in birds and in mammals.

Birds, like all warm-blooded creatures, have the heart divided into four cavities--two ventricles and two auricles--those of the right side being completely separated from those of the left. The whole is enclosed in a pericardium, a thin, but strong, membrane. The right ventricle has thin muscular walls, and almost completely envelopes the left. The right auricle has a remarkable valve in the shape of a fleshy leaflet, which appears almost to be a portion of the inside of the ventricle that has become detached from the partition between the two ventricles. The blood, under certain circumstances, passes between this septum, or partition, and the leaflet, into the auricle; but when the beat of the heart takes place (the systole), the septum, being convex, is forced against the leaflet on the other side of the auricolo-ventricular opening, and the passage of the blood, through this, is prevented. The valve between the stout-chambered left ventricle and auricle does not present this structure, but is divided into two or three lobes attached to tendinous processes. At the origin of the great vessels--the pulmonary artery and the aorta--there are three valves, semi-lunar in shape and by name. And this last vessel, often having given off the coronary artery to the heart itself, is curved to the right, and then passes backwards to go down the body. The blood from the body is collected into three large veins--two anterior venæ cavæ and one posterior.

The lymphatic system is well developed, and of the so-called “lymphatic hearts,” which are well known in the Frog, the posterior ones have been observed in some, and especially in the Ratite birds.

The lungs, or organs in which the blood effects an exchange of its gases with the outer air, are paired, and set on either side of the heart. As is elsewhere mentioned, the nostrils are not provided with muscles, and there is no epiglottis sufficiently well developed to cover the entrance into the long tube, or trachea, which runs down the neck. This tube, which does not always take a straight course, is essentially made up of a number of rings of cartilage, which are for the greater part perfect, and not, as in man, imperfect rings. The bronchi which are given off from this tube, to the right and left, have their rings imperfect, and they do not show that two-forked mode of division which is so characteristic of mammals. The lungs are of a rosy colour, and of a comparatively small volume; they are marked externally by depressions corresponding to the characters of the vertebræ and ribs, to which latter they are firmly attached, and they are not divided into lobes; in their texture they are spongy; the air-tubes are given off from them at right angles to the main air-passage; these run nearly parallel to one another, and contain in their walls the true tissue of the respiratory organ. The air-tubes are also connected with the air-cells, which are arranged in so remarkable a manner as to deserve a full account.

They are found in all birds with the exception of the Apteryx, according to Professor Owen. Our knowledge of their existence is primarily due to the illustrious William Harvey, while it is to the distinguished anatomist, John Hunter, that we owe our knowledge of the very curious fact that these air-passages and sacs communicate also with the cavities of some of the bones of the skeleton. Though these sacs are not by any means highly vascular, or supplied with vessels to the same rich extent as are the lungs, they are nevertheless of enormous importance to the bird; thus, they diminish the specific gravity of the animal. For example, taking a bird which weighs 1,600 grammes, and has a volume of 1,230 cubic centimetres--or a specific gravity of 1·30 (1600/1230) it has been calculated (Bert) that 200 cubic centimetres of air can be introduced; now these centimetres would weigh ·22 of a gramme, so that the specific gravity of the animal would be reduced to 1·05 ((1600+0·22)/(1230+200)) or (1600·22/1520). Again, the air which is taken into the lungs is, in high-flying birds, often of an extremely low temperature; but this air is not only brought into contact with that of the lungs, but also with that which has been warmed in the abdominal cavity. And again, the air is often very dry--as it is for the Ostrich on the desert plains of Africa--but the air from the air-sacs contains a large amount of moisture. Of the proper air-sacs there are nine; of these, four--the two anterior and the two posterior thoracic--lie in the thorax (breast) proper; three--the right and left cervical, and the sac between the clavicles--lie in front of the thorax; while the last two are found behind it and in the abdomen. From all of these, with the exception of those within the thorax, communications are, or may be, given off to the bones of the vertebral column, to the humerus, to the bones of the thigh, and to the sternum and the ribs; but there is no communication between these sacs and the air-spaces which are so constantly found in the bones of the skull, and which are in connection with the air-cavities of the ear and of the nose. The inter-clavicular sac has been observed to be covered with a thick layer of muscle in those birds, at any rate, which perform somersaults, and it has been suggested that this layer of muscle is capable of driving the air in the sac backwards. It is obvious that such an operation would send the centre of gravity of the animal nearer the head, and would, so far, be of assistance in the execution of the curious movement alluded to.

It has been suggested that the air-sacs are of assistance in increasing the resonance of the bird’s voice. Be this as it may, attention must now be turned to the organ of voice. This organ may take one of three forms, or, if absence is to be counted, four. There is no organ of voice in the Ratitæ, or in the American Vultures (Cathartidæ). It is, when present, remarkable for being developed at the lower, and not at the upper, end of the trachea; while the true vocal cords, which, by their vibration produce the notes of the human voice, are altogether and always absent from the larynx; in other words, the vocal organ is not the larynx, but an organ seated at a lower level, and known as the syrinx. This instrument may, further, be formed in the trachea alone (as in some American Passerines), or in the bronchi alone (as in Steatornis), or at the point at which the tracheal and bronchial tubes pass into one another (as in the majority of singing birds).

The last-mentioned, or bronchio-tracheal syrinx, consists of the following parts; (i.) a tympanic chamber formed by the union of some of the lower rings of the trachea; (ii.) a membranous septum separating from one another the tracheal orifices of the two bronchi; (iii.) on either side a tympaniform membrane, formed on the inner side of the uppermost bronchial rings; in consequence of this these bronchial rings are not complete circles; their mucous membrane is developed into a fold which bounds one side of a cleft which is formed by the presence on the other side of the above-mentioned tympaniform membrane. The air which passes through these bronchial clefts sets in vibration the membranes which bound them, while the character of the note is affected by the position of the bronchial half-rings, and the length of the column of air in the trachea. These rings have their positions changed by five lateral muscles, which act on their ends, and so rotate them. The principle variations in the characters of the muscular supply of the organ of the voice were long ago worked out by Johannes Müller, the famous German anatomist and physiologist.

It is also to this observer that we owe our first information with regard to the bronchial syrinx of Steatornis; the anatomy of this animal was also investigated by the late Prof. Garrod, who gave the following account of its vocal apparatus:--“Each semi-syrinx, as it may be termed, is formed on the same principle as that of the combined organ in most of the non-singing birds. Taking for description that of the left side, it is found that the thirteenth bronchial ring is complete, though considerably flattened from side to side; the fourteenth is not complete in the middle of its upper surface; it is a little longer from before backwards than the one above, and not so long as the one following it. The fifteenth is only a half ring, its inner portion being deficient; it is slightly convex upwards, and articulates, both at its anterior and posterior ends, with the fourteenth incomplete ring and the sixteenth half-ring. The sixteenth half-ring is concave upwards, and so forms an oval figure in combination with the one above, which is filled with a thin membrane to form part of the outer wall of the bronchus. There is a membrane also between the ends of these and the succeeding half-rings, which completes the tube of the bronchus internally.”

The ducts from the urinary organs open to the exterior through the cloaca, into which, as already mentioned, the digestive tube also opens. The chief point with regard to the urinary secretion of birds is the fact that it is semi-solid, and that it contains a quantity of the substance known as uric acid. The kidneys are placed some way back and near the cloaca; they are set on either side of the spinal column, between the transverse processes of the sacral vertebræ, and are generally divided into three portions of greatly varying size. On their inner edge are given off the ureters, which pass on each side to enter separately into the before-mentioned cloaca.

The right ovary of birds is always atrophied, and it is in rare cases only that rudiments of it are found (namely, in the diurnal Raptores). The oviduct is a coiled canal, the lower portion of which has strong, muscular walls, while internally the characters of its surface vary according to the substance which the glands of different regions add to the descending egg. The right oviduct is not so completely atrophied as is the ovary of the same side. This duct opens into the cloaca through which the egg passes to reach the outer world; as further development is so largely independent of the mother, the female organs offer no peculiarities of arrangement, or complexities of structure.

All birds lay eggs, or, in other words, the born young are not carried about by the mother till the time of birth. The advantage of this to a flying animal is so obvious that we may pass at once to describe the egg of a common fowl. The shell, which consists of organic matter and lime-salts, is found to be formed of two layers; it is in the outer one only that pigment is found. Both layers are traversed by canals, through which air can pass only when the shell is dry; that is to say, the outer pores of the shell are closed under the influence of moisture. This may be seen by removing the outer layers, when air or water will pass in quite easily. These canals are said to be branched in the Ratite birds, and to be simple in the Carinatæ. The shell is lined by the shell-membrane, which, again, is made up of two layers. At the broad end of the egg these two layers are separated from one another, and so give rise to that air-chamber which is found in stale eggs, and increases in size as the egg grows older and the yolk evaporates.

The shell-membrane is in direct contact with the white of the egg (albumen). This, in its fresh state, consists of fluid albumen, arranged in layers, which are separated from one another by networks of fibres, in the meshes of which, however, fluid albumen is also to be found. There are, further, two special sets of fibrous cords in the white of the egg; these extend somewhat along the long axis of the egg, though they do not reach to the shell-membrane. From their bead-like character they are known as chalazæ (hailstones), but their more common English name is that of the “tread.”

The “white” is separated from the yolk by the so-called vitelline (or yolk) membrane; the greater part of this yolk is known as the yellow yolk, and is made up of minute albuminous granules, but its outermost part is formed of a thin layer of a somewhat different substance, which goes by the name of the white yolk. The spheres of this latter are still smaller than those of the yellow yolk, and they are also found to form layers at various levels in it. At one point the white yolk becomes a good deal thicker, and forms, as it were, a pad for a small white disc, which, in ordinary circumstances, is always found uppermost when an egg is opened. This disc is formed of an encircling white rim, and within it there is a rounded transparent region, the centre of which is more opaque.

This region is known as the blastoderm, and is that part of the egg from which the chick, with its organs and complicated vessels, muscles and bones is soon to be developed. In the laid egg, this blastoderm consists of two layers of cells, as do at a certain stage the eggs of all but the very simplest of animals. The dissection of a laying fowl will probably reveal the presence of eggs at an earlier stage, and from their study the following history has been made out: the ellipse-shaped egg, when about to leave the ovary, is a yellow body enclosed in a fine membrane, and possessing at one pole a small (germinal) disc; this disc contains a smaller germinal vesicle, and a still smaller germinal spot; when this body is ripe, it escapes from its enclosing capsule, and the germinal vesicle disappears. As the egg passes down the oviduct the albumen becomes deposited around it, and part of it is converted into the shell-membrane. The egg now becomes subjected to a thick, white fluid, which is gradually converted into the shell.

While these additions to the substance of the egg are going on, the germinal disc undergoes the remarkable process known as segmentation, in which it becomes divided into two, four, eight, sixteen, thirty-two (and so on) masses, which arrange themselves in two distinct layers, the presence of which has been already noted in the laid egg.

This is not the place in which it is possible to follow out the various future changes undergone, but the condition of the young birds on escaping from the egg is widely different in some of the larger groups of birds. Some young birds, on their exclusion from the egg, are able to shift for themselves, and are covered with down; while others are born naked and helpless, and require food from their parents for some time after they are hatched. Of the first section, an ordinary chicken is a familiar example, while a young Thrush or a Sparrow illustrates the second. There are, however, manifest exceptions to this rule, as in the Herons, for instance, where the young are densely clothed with feathery down, but are helpless for a long time after they are hatched.

Finally, it must be stated that all birds possess an oil-gland (known as the uropygial), situated near the tail, with which they clean and dress their feathers. Attention has already been called to this gland in the foot note on p. 245.

Before commencing the special part of the present article, it may be useful to give a slight sketch of the classification which it is proposed to follow throughout its course.

CLASS AVES.

DIVISION I. CARINATÆ: CARINATE BIRDS.

ORDER I.--ACCIPITRES: BIRDS OF PREY.

SUB-ORDER I.--FALCONES: FALCONS.

Family I.--Vulturidæ Vultures. „ II.--Falconidæ Hawks.

Sub-Family I.--Polyborinæ Caracaras. „ II.--Accipitrinæ Long-legged Hawks. „ III.--Buteoninæ Buzzards. „ IV.--Aquilinæ Eagles. „ V.--Falconinæ Falcons.

SUB-ORDER II.--PANDIONES: OSPREYS.

SUB-ORDER III.--STRIGES: OWLS.

Family I.--Bubonidæ Owls proper. „ II.--Strigidæ Barn Owls.

ORDER II.--PICARIÆ: PICARIAN BIRDS.

SUB-ORDER I.--ZYGODACTYLÆ: CLIMBING BIRDS.

Family I.--Psittaci Parrots.

a.--Psittaci proprii.

Sub-Family I.--Camptolophinæ Cockatoos. „ II.--Androglossinæ Fleshy-tongued Parrots. „ III.--Conurinæ Conures. „ IV.--Platycercinæ Parrakeets. „ V.--Strigopinæ Owl Parrots.

b.--Psittaci orthognathi.

„ VI.--Trichoglossinæ Brush-tongued Parrots.

Family II.--Cuculidæ Cuckoos. „ III.--Indicatoridæ Honey-guides. „ IV.--Musophagidæ Touracoes. „ V.--Picidæ Woodpeckers. „ VI.--Rhamphastidæ Toucans. „ VII.--Capitonidæ Barbets.

SUB-ORDER II.--FISSIROSTRES: WIDE GAPING BIRDS.

Family I.--Galbulidæ Jacamars. „ II.--Bucconidæ Puff Birds. „ III.--Alcedinidæ Kingfishers. „ IV.--Bucerotidæ Hornbills. „ V.--Upupidæ Hoopoes. „ VI.--Meropidæ Bee-eaters. „ VII.--Momotidæ Motmots. „ VIII.--Coraciadæ Rollers. „ IX.--Trogonidæ Trogons. „ X.--Caprimulgidæ Goatsuckers. „ XI.--Cypselidæ Swifts. „ XII.--Trochilidæ Humming-birds.

ORDER III.--PASSERIFORMES: PERCHING BIRDS.

SECTION A.--ACROMYODI: SINGING BIRDS.

SUB-ORDER I.--TURDIFORMES: THRUSH LIKE BIRDS.

GROUP I.--COLIOMORPHÆ: CROW LIKE PASSERES.

Family I.--Corvidæ Crows.

Sub-Family I.--Corvinæ Crows proper. „ II.--Fregilinæ Choughs.

Family II.--Paradisiidæ Birds of Paradise. „ III.--Orioliidæ Orioles. „ IV.--Dicruridæ Drongos. „ V.--Prionopidæ Wood-shrikes.

GROUP II.--CICHLOMORPHÆ: THRUSH-LIKE PASSERES.

Family VI.--Campophagidæ - - - - Cuckoo-shrikes. „ VII.--Muscicapidæ - - - - - Flycatchers. „ VIII.--Turdidæ - - - - - - - True Thrushes.

Sub-Family I.--Turdinæ - - - - Thrushes. „ II.--Sylviinæ - - - - Warblers.

Family IX.--Timeliidæ - - - - - - Babbling Thrushes.

Sub-Family I.--Troglodytinæ - - Wrens. „ II.--Brachypodinæ - - Bulbuls. „ III.--Timeliinæ - - - Babblers. „ IV.--Cisticolinæ - - Grass-warblers. „ V.--Miminæ - - - - - American Babblers.

Family X.--Laniidæ - - - - - - - Butcher-birds. „ XI.--Vireonidæ - - - - - - Greenlets. „ XII.--Paridæ - - - - - - - Titmice.

GROUP III.--CERTHIIMORPHÆ: CREEPERS.

GROUP IV.--CINNYRIMORPHÆ: HONEY SUCKERS.

SUB-ORDER II.--FRINGILLIFORMES: FINCH-LIKE BIRDS.

Family I.--Motacillidæ - - - - - Wagtails. „ II.--Mniotiltidæ - - - - - American Warblers. „ III.--Cærebidæ - - - - - American Creepers. „ IV.--Diceidæ - - - - - - - Flower-peckers. „ V.--Ampelidæ - - - - - - Chatterers. „ VI.--Hirundinidæ - - - - - Swallows. „ VII.--Tanagridæ - - - - - - Tanagers. „ VIII.--Fringillidæ - - - - - Finches. „ IX.--Icteridæ - - - - - Hang-nests.

SUB-ORDER III.--STURNIFORMES: STARLING-LIKE BIRDS.

Family I.--Ploceidæ - - - - - - Weavers. „ II.--Sturnidæ - - - - - - Starlings. „ III.--Artamidæ - - - - - - Wood-swallows. „ IV.--Alaudidæ - - - - - - Larks.

SECTION B.--MESOMYODI: SONGLESS BIRDS.

Family I.--Menuridæ - - - - - - Lyre-birds. „ II.--Pteroptochidæ - - - - Bush-wrens. „ III.--Dendrocolaptidæ - - - Spine-tails. „ IV.--Formicariidæ - - - { American Ant-thrushes. „ V.--Pittidæ - - - - - - { Old-World Ant-thrushes. „ VI.--Tyrannidæ - - - - - - Tyrant-birds. „ VII.--Cotingidæ - - - - - - American Chatterers. „ VIII.--Pipridæ - - - - - - - Manakins. „ IX.--Eurylæmiidæ - - - - - Broadbills. „ X.--Phytotomidæ - - - - - Plant-cutters.

ORDER IV.--COLUMBÆ: PIGEONS.

ORDER V.--GALLINÆ: GAME-BIRDS.

Family I.--Cracidæ - - - - - - - Curassows. „ II.--Opisthocomidæ - - - - Hoatzins. „ III.--Phasianidæ - - - - - Pheasants. „ IV.--Meleagridæ - - - - - Turkeys. „ V.--Tetraonidæ - - - - - Grouse. „ VI.--Pteroclidæ - - - - - Sand-grouse. „ VII.--Turnicidæ - - - - - - Hemipodes. „ VIII.--Megapodidæ - - - - - Megapodes.

ORDER VI.--GRALLÆ: WADING BIRDS.

Family I.--Rallidæ - - - - - - - Rails. „ II.--Scolopacidæ - - - - - Snipes. „ III.--Charadriidæ - - - - - Plovers. „ IV.--Otididæ - - - - - - - Bustards. „ V.--Gruidæ - - - - - - - Cranes. „ VI.--Psophiidæ - - - - - - Trumpeters.

ORDER VII.--HERODIONES: HERONS.

Family I.--Ardeidæ - - - - - - - Herons proper. „ II.--Ciconiidæ - - - - - - Storks. „ III.--Plataleidæ - - - - - Spoonbills. „ IV.--Phænicopteridæ - - - Flamingoes.

ORDER VIII.--ANSERES: GEESE.

Family I.--Palamedeidæ - - - - - Screamers. „ II.--Anatidæ - - - - - - - Ducks.

ORDER IX.--STEGANOPODES: PELICANS.

Family I.--Fregatidæ - - - - - - Frigate-birds. „ II.--Phæthontidæ - - - - - Tropic-birds. „ III.--Pelecanidæ - - - - - Pelicans.

ORDER X.--GAVIÆ: SEA-BIRDS.

Family I.--Laridæ - - - - - - - Gulls. „ II.--Procellariidæ - - - - Petrels.

ORDER XI.--PYGOPODES: GREBES.

ORDER XII.--IMPENNES: PENGUINS.

ORDER XIII.--CRYPTURI: TINAMOUS.

DIVISION II.--RATITÆ: STRUTHIOUS BIRDS.

DIVISION III.--SAURURÆ: LIZARD-TAILED BIRDS.

It has been already stated that birds are divisible into three great sections, and attention is now directed to those which have a keel to the sternum, and which are good flyers--the Carinate Birds (CARINATÆ).

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