British mammals; an attempt to describe and illustrate the mammalian fauna of the British islands from the commencement of the Pleistocene period down to the present day

Front matter

LIBRARY 0

THE WOBURN LIBRARY

OF

Appendix

LIST OF BRITISH MAMMALIA 379

INDEX 393

LIST OF COLOURED ILLUSTRATIONS

1. RED DEER (Cervus tlaphus) : August Frontispiece

2. THE COMMON RORQUAL WHALE (Bahznoptera musculus) . . Facing page 48

3. THE COMMON MOLE (Talpa europaa) ,, 60

4. FOXES (Cants vulpes) „ 120

5. THE LAST BRITISH WOLF „ 130

6. OTTERS (Lutra vulgaris) ,, 140

7. BADGERS (Meles taxus) „ 146

8. THE PINE MARTEN (Mustela martes) ,, 150

9. THE WILD CAT (Felis catus) ,, 182

10. THB COMMON SEAL (Phoca vitulina) „ 196

11. HARES (Lepus europaus) in an Oatfield : Evening ... ,, 22

12. SQUIRREL (Sciurus vulgaris} robbing Ring Dove's Nest . . „ 228

(The coat is that of the end of the winter season, say April.)

13. THE WATER VOLE (Microtus amphibius) ,, 252

14. ROE DEER (Capreolus caprtea): September . . . . ,, 292

15. FALLOW DEER (Cervus dam*) ,, 308

16. ENGLISH WILD CATTLE (Bos taunts). Cadzow breed . . ,, 362

Facing 82 xiv LIST OF BLACK-AND-WHITE ILLUSTRATIONS

AGE

22. Skeleton of a Bat's Hand 78

23. Ears of Bats, to show Tragus, Absence of Tragus, and Development of

Antitragus 8l

Long-eared Bat (Plecotus auritus)

Common Bat hanging by its Thumbs .....

Common Bat (Pipistrellus pipistrellus') hanging by its Feet .Bat hanging with folded Wings and Tail ....

25. Bones of a Bat's Leg and Foot 84

26. Serotine Bat ( Vespertilio serotimis) : to show (a) shape of ear ; (£) naked

three-cornered space on under lip ;. (i) remains of sucker disc on the ball of thumb ; (cf) point of departure of wing membrane from base of toes ; (e) calcaneum or spur.; (/) post-calcaneal lobule and interfemoral membrane j (g) degree to which tail projects beyond the interfemoral membrane. . 85

27. Great or Noctule Bat (Pterygistes noctuld) 87

28. Skull of Noctule Bat (l£ times natural size) 88

29. Front of Skull of Noctule Bat, to show separation between incisor teeth and

large canines (3 times natural size) 88

30. Head of Noctule Bat (nearly twice natural size) 89

31. Head of Pipistrelle, or Common Bat {Pipistrellus pipistrellus) . . . .91

32. Head and Foot of Daubenton's Bat 95

33. Head of Bechstein's Bat. Nearly twice natural size 97

34. Head of Common Continental Bat (Myotis myotis). Natural size ... 99

35. Head of Whiskered Bat. (2^ times natural size) IOI

36. Ear of Notch-eared Bat (Myotis eniarginatus). Twice natural size . . . 102

37. Head of Barbastelle Bat (Barbastella barbastellus). Note ear membranes

joining over forehead, groove along nose, and eyes fairly close together. Twice natural size 103

38. Nose and Muzzle of Barbastelle Bat (3 times life size) 103

39. A. Ears of the Long-eared Bat (half again as large as natural size) ; B. The

Long-eared Bat (life size), showing ears pressed against the sides and tragus erect 105

40. Nose and Muzzle of Long-eared Bat. (3 times natural size) . . . .106

{The Greater Horseshoe Bat (Rhinolophus ferrum-equinuni) . . 1 The Common Bat (Pipistrellus pipistrellus) . . . . l J FtutnS

42. Head of Greater Horseshoe Bat (Rhinolophus ferrum-equinum), to show

nose leaf. Note also absence of tragus and large development of lobe

of outer margin of ear. Nearly twice natural size 109

43. Nose Leaf of Greater Horseshoe Bat in Profile (slightly less than natural size) . no

44. Nose Leaf of Lesser Horseshoe Bat (Rhinolophus hipposiderus). Twice natural

size. 112

45. Jaws of Otocyon megalotis (to show four molar teeth in each jaw, etc.) . .114

46. Angle of the Lower Jaw in Otocyon, as compared with the angle of the

Jaw in Cants cancrivorus (Crab-eating Dog) and in Wolf . . . • 1*5

LIST OF BLACK-AND-WHITE ILLUSTRATIONS xv

PAGE

47. Examples of Fourth Upper Premolar (the Upper Carnassial Tooth) in various

Carnivores 117

(The Common Fox (Canis vulpes) ) The Wolf, European Type (Canis lupus) j FactnS

( British Cave Lion (Felis leo spelaa) 1

49< | British Cave Bear (Ursus spelceus) ^Facing 134

[The Common Otter \

5°'j The Common Otter (Lutra vulgaris) \Factng 138

{The Pine Marten (Mustela martes) 1 The Badger (Meles taxus) j" **** *44

52. The Polecat (Putorius fatidus) Facing 154

53. The Common Stoat (Putorius ermineus). Summer coat . . . Facing 158

54. The Weasel (Putorius nivalis) Facing 162

55. Examples of Upper Canine Tooth in Lion and in two Machairodonts

(natural size) I71

56. Gape of Jaws in a British Sabre-toothed "Tiger" (Machairodus cultridens) . 173

{The Ferret, domesticated form of Polecat (Putorius fxtidus) . . 1 The Wild Cat (Felis catus) L*"

58. Fore Paw and Hind Paw of Common Seal compared with Fore Paw and

Hind Paw of Sea Lion 190

59. Premolars and Molar, Upper Jaw, of Common Seal 195

60. The Harp Seal {Phoca grcenlandica) 2OI

61. The Gray Seal (Halichcerus grypus). Adult and young . . . Facing 204

62. Head of Hooded Seal (Cystophora) 207

63. Wild Rabbits (Oryctolagus cuniculus) Facing 212

64. The Mountain Hare (Lepus timidus). Winter coat in Wicklow

Mountains, Ireland Facing 218

I The Common Hare (Lepus turopteus) I zr •

65. -\ r facing 220 I The European Beaver (Castor fiber) J

f The Squirrel (Sciurus vulgaris) 1 «• •

'1 The Common Dormouse (Mtiscardinus avellanarius) . . • j

67. Molar Teeth of Squirrel, Rat, and Water Vole (Microttts) for Comparison

(twice natural size) 238

f Long.-tailed Field or Wood Mouse (Mus sylvaticus) . „ J Harvest Mouse (Mus minutus) \. F ' p

j Red Bank Vole (Evotomys glareolus)

I Black Rat (Mus rattus)

f Brown Rat (Mus decumanus)

69'| Short-tailed Field Vole (Mzcrotus agrestis) J "**& 2S°

70. Pattern of Enamel and Dentine on Surface of Molar Teeth of African and

Indian Elephants 263 xvi LIST OF BLACK-AND-WHITE ILLUSTRATIONS

PAGE

71. The Mammoth (Ehphas primigenius) ....... Facing 266

72. Prjevalski's Horse (Equus przevalskii) ..... Facing 274

73. The Evolution of the Horse's Tail ......... 275

74. Bones of the Hand or Lower Front Limb in Modern Artiodactyles, to

illustrate Gradual Disappearance of the Side Fingers ..... 281

(Wild Sow and Young . . ........ 1 Irish Pig ............ j- Facing 286 Wild Boar (Sus scrofa) ......... J

76. Head and Neck of Roebuck, to show White Markings on Neck and Black

Mark across Muzzle . .

77. Examples of Roe Deer's Antlers, Ancient and Modern Fallow Deer (Cervus dama)

f

Fallow Deer (Unspotted Form) ........

79. Examples of Fallow Deer's Antlers .......

80. The Gigantic Irish Deer (Cervus megaceros} \ Antlers and Skeleton. f Red Deer : Stag (Cervus elaphus) ......

8iJ Red Deer: Hind and Fawn ........

\ Red Deer : Hinds .........

82. Gland Tuft on Hind Leg of Red Deer ......

83. Stag in Early March without Antlers (to show Pedicle of Antlers)

84. Red Deer's Antler of Pleistocene Period : dug up at Durham (British

85. Example of well-developed Antlers in Stag of Twelve or Thirteen Years Old 328

86. The Progressive Growth of a Red Deer's Antlers (first year hornless) . 330-31

87. Examples of the Development of the "Cup" or Terminal Fork of the Red

J The Saiga (Saiga tatarica) 1

'1 The Musk Ox (Ovibos moschatus) f

.

1 J

89. Horns of a Ram (jOvis aries), from Achill Island, off the West Coast of Ireland 349 f Highland Sheep (Ovis aries) ........ "\

90. J Soa Sheep, St. Kilda (Ovis aries') ....... v Facing 350

(_ Female Corsican Mouflon (Ovis musimon), to show Tail I Horns of Extinct English Bison (Bos priscus) 91 "I Skull of Extinct Aurochs (Bos primigenius) FannS 356

f European Bison (Bos bonasus) from Lithuania ..... 1

2< JHead of English Wild Bull, Chartley Breed (Bos taunts') . . J Faa"S 3S8

J English Wild Cattle : Bull of the Chartley Breed (Bos taurus) • 1 , .

3> | English Wild Cattle: Cow and Calf (Chartley Breed) . . .J FaC"'g 362

(Domestic Cattle : Kerry Bull (Bos taurus longlfrons) . . .1

Domestic Cattle : Long Horn Bull ....... f FacinS 3$4

95. Probable Centres of Development and Migration Routes of Primates . . 369

CHAPTER I P REFArORT

SOME explanation and apology of and for the presentation of this book to the reading public is necessary, seeing that the subject of British Mammalia has been dealt with before in a general sense by such able writers as the late William Macgillivray, the late Professor Thomas Bell, and Mr. Richard Lydekker ; while groups or species of British beasts have been described in detail by Sir William Flower, the late Dr. Dobson, Mr. Oldfield Thomas, Dr. R. F. Scharff, Mr. W. E. de Winton, Professor Boyd Dawkins, Mr. J. E. Harting, Mr. Harvie- Brown, the Rev. H. A. Macpherson, Messrs. W. Thompson (Irish Mammals), Aubyn Trevor-Battye, W. Buckley, John Guille Millais,1 Lionel Adams, G. Barrett Hamilton, F. G. Aflalo, C. J. Cornish, and Dr. A. B. Smith Woodward.2 Mr. T. McKenny Hughes in 1896 wrote an admirable treatise on the origin of the breeds of domestic cattle. Mr. F. E. Beddard

1 The finest draughtsman of British beasts and birds who has yet appeared on the scene. His monographs of the Deer and the Wild Fowl of the British Islands should have been crowned by a British Academy. His study of African Mammals in "A Breath from the Veldt" is unrivalled, and will probably remain so.

2 Who, together with the late Sir Richard Owen, Professor Boyd Dawkins, and Mr. Richard Lydekker, has done much to describe the ancient mammalian fauna of the two British Islands.

has dealt with Mammalia generally, his work in the Cambridge Natural History Series being the latest study of the subject, and in this book a good deal of incidental information is given regarding the mammals of the British Islands. The admirable work published by Dr. J. H. Blasius in 1857 on the mammalian fauna of Germany and Central Europe contains much information on the structure and habits of beasts which also inhabit Britain ; and the great German palaeontologist, Dr. Karl A. von Zittel, in his classical Handbook of Paleontology^ has incidentally described and illustrated a good many extinct British mammals. Students who may be attracted to the study of British mammals are also advised to read the files of such periodicals as the Zoologist (London) and the Field newspaper, both of which contain first-hand information of great value on British Zoology. To all of the above-mentioned writers and publications the author of this book is greatly indebted for information, and to these separate works he refers such of his readers as are desirous of learning something more about the beasts of their own country, and who might wish for further detailed information connected with the anatomical structure or life-habits of the British Mammalia beyond what can be given within the space of this volume.

To the accumulated and carefully sifted facts recorded by this formidable array of writers the author has ventured to add his own observations and theories. Although a good deal of his time has been spent in Africa, he has nevertheless from his youth up been a student of the British Mammalia in all parts of the United Kingdom. His first interest in British beasts was no doubt prompted by their aesthetic aspect, their beauty of outline or colour ; and though he has since become entangled in the fascinations of comparative anatomy, the strongest attraction which beasts and birds still possess for him lies in the part they fill (or should fill) in British landscapes.

It may be necessary to apologise to the world outside Britain for any attempt to attach importance to our existing mammalian

PREFATORY 3

fauna. This has become so reduced in numbers, so scarce and little evident in many of the existing species, that we should almost appoint an annual national day of humiliation for our poverty in this respect, a poverty due to the past ravages of ourselves and our ancestors, and almost unexampled in any other part of the habitable world, except New Zealand or the Pacific Archipelagoes.

This book, indeed, had it only dealt with the few well-known wild beasts still lingering in Great Britain and Ireland, would not have been worth compiling. But the author has endeavoured to deal as amply as possible with recently extinct British mammals ; and to expatiate on the interesting problems concerning the origin and migration routes of the recent mammalian fauna which has inhabited these islands since the close of the Tertiary Epoch. As one drives through the dreary streets of Outer London, or gazes on the devastation of the Isle of Sheppey, the over-building at Bournemouth, the smug villas of Torquay, the paper mills of the Mendip Hills, the factory chimneys of Yorkshire, the desolated bogs of Ireland, and the hideous prosperity of Lanarkshire and Lancashire, it is possible to derive some consolation by recalling in imagination the African elephants and the hairy mammoths, the gigantic wild cattle and clumsy horses, the sabre-toothed " tigers," the lions larger than those now existing, the enormous cave bears, spotted hyasnas, gigantic Irish deer, beavers, wild boars, and wolves which severally or together made those regions a scene of fascination and wonder even to Palaeolithic and Neolithic man. Like the writers and statesmen of modern Greece and Spain, the author's thoughts as a student of Mammalia are mentally fixed upon the glorious past, and his survey of the present is a whimpering apology. He who would fain have described how the sabre-toothed " tiger " severed the spinal column of the megaceros deer with its trenchant tusks ; how man, naked and unashamed, and armed with weapons which were poor as compared with those of the Congo Pygmy, matched himself against the mammoth and caught the aurochs in a pitfall : he, instead, must twitter on the ferocity of the weasel and relate park anecdotes of park-fed beasts. There are lessons, however (one must humbly admit), to be learnt even from the nineteen varieties of the wood mouse and the violent amours of the mole.

But as it is the aesthetic aspect of the Mammalia which first attracted the author of this book, it is that on which he most wishes to insist in his arguments. If in any way he has brought home to his readers the importance of Mammalia to the landscape aspects of Britain, the desirability of preserving and strengthening the species that remain (not because they are good for food or sport or unobstructive to the aims of the farmer or the citizen, but because they are beautiful or stimulating to intellectual interest), he will not have written in vain. Man does not live by bread alone. He requires to fill his life with an enjoyment of beauty, a bracing of the nerves by wholesome danger, a stimulation of the intellect by the mysteries of Creation. If we succeed in extirpating our wild beasts and birds, or in reducing a few of them to fattened, pied, frilled monstrosities (an action which will probably proceed concurrently with the extermination of our native flora by field clubs, costermongers, and agriculturists), life in England, Scotland, or Ireland will no longer be worth living, since man cannot live by bread alone, nor can roast beef and potatoes wholly atone for the extirpation of the aurochs and the Osmunda fern. One may admire the pheasant greatly as a beautiful bird, and blind oneself to all peevish evidence brought forward to show that it is not indigenous ; but one should admit that the weasel is quite as beautiful and half again as interesting. Still more, the polecat ; while the wild cat should be permitted to make moderate ravages on live-stock, and the damage done be paid by an interested countryside from out of the rates.

It was distressing to read how, during a yachting cruise in the summer of 1902, the suite that accompanied very distinguished persons gleefully took advantage of their proximity to little-frequented Scotch islands and islets to shoot and leave, kill uselessly without excuse, quite a large number of the few seals which still remain in Scottish waters. The otter is being

PREFATORY 5

rapidly extinguished in Wales, Devonshire, and Sussex, by unreflecting, red-faced, well-meaning, church-going, rate-paying persons on the plea that it eats salmon or trout.1 Now, what nonsense this is ! No trout that was ever served on a dish is as good as a fried sole. Salmon is a handsome-looking fish, so far as fish go, and its flesh, though very provocative of biliousness, is liked by a large number of people. But salmon is produced in such enormous abundance in North America and Norway, and is so very unlikely (owing to its habit of resorting to the sea) to become exterminated in British waters by the otter, that it would be a shame if this remarkable aquatic weasel, so beautiful an object as an adjunct to a stream landscape, were extirpated, destroyed, or even rendered wild, to gratify the angler's craze — a craze nearly as modern as golf and cricket, but not so picturesque or beneficial to athletic development. It is necessary to insist, for the future happiness of the world, on the aesthetic value of beasts, birds, and reptiles. Amphibians and fish are less worthy of regard, partly from the fact that as they live almost entirely in the water they play no part in the beauty of landscapes. As regards all invertebrates, one may disregard, destroy, or disprotect all except those crustaceans that are good for food. Butterflies and some beetles are charming in coloration and outline, but the grandest of butterflies is feeble in aesthetic value compared to a bird, and the grubs of both butterflies and beetles do unmeasured harm. Fresh-water fish should not be protected against the ravages of the higher vertebrates : they must take their chance. As regards sea-fish, many forms are either beautiful in coloration, imposing in bulk, or fantastic in shape, and therefore provocative of interest. But as it is a most exceptional incident in our lives to put on a diver's dress and

1 Here is an extract from a recent number of the Daily Graphic : " The Crowhurst Otter Hounds. — The new pack of hounds which have just been started in East Sussex to hunt the country in the neighbourhood of Hastings is to be called the Crowhurst Otter Hounds. They propose to begin operations on the i8th of this month."

descend below the level of the water, we derive but little aesthetic enjoyment from fish, and though they are estimable as a food supply, their natural domain is so vast that the only mammal who can ever bring any species of them near extinction is man himself. The present writer has little sympathy with those well-meaning but misdirected persons who, loving the Mammalia, and feeling starved in their affections as British residents, introduce into their parks and domains kangaroos, African antelopes, ostriches, or Indian humped cattle. What they ought to do (what some great landowners have done) is to reinforce and protect dwindling British species, and reintroduce those lost forms which were co-existent with man in prehistoric times, and which may still be found lingering in holes and corners of Europe, Asia, and North America. One does not wish to be unreasonable ; and few would propose the letting loose of lions in the hope of re-developing a Fells spel<ea, or the turning out of Indian elephants to stand the climate as best they might and gradually recover the shaggy hair and the tusks of the mammoth. These creatures, and the spotted hyaena, leopard, glutton, and hippopotamus, might prove too antagonistic to human comfort and prosperity in these crowded islands : we must be content to keep them in menageries. But there is no reason why we should not prudently reintroduce the European bison, the musk ox, the reindeer, the boar ; perhaps the bear, the beaver, the saiga antelope, the lynx, and the wolf. We might use all our efforts to stimulate the wild white cattle of the northern parks, forbidding the destruction of red and black calves, and so hoping that, in time, they might regain the stature and appearance of their forefather the aurochs. Horses of the Connemara breed might be encouraged to run wild in paradises like Achill Island and the New Forest till they reverted to the appearance of Prjevalski's horse. Of course, if these islands are to contain a population of (say) a hundred millions, it must be at the expense of destroying all beauty and all specially British characteristics of landscape, fauna, and flora. No doubt, without detriment to the picturesque, the population of Ireland might

PREFATORY 7

be allowed to rise to fifteen millions, and that of Scotland to the same figure, with additional increases to the population of England and Wales, more especially in the existing towns. But the time must come when we shall have to make up our minds, as a nation, to increased emigration towards less thickly inhabited parts of the world, or to the artificial checking of population. Why should we not copy Japan, where a very large population apparently can co-exist with a rich fauna and flora, and with landscapes of superb natural beauty ? As regards both animals and plants in that country, the explanation probably lies in the fact that the Japanese have no craze for destroying birds and beasts in the cause of " sport," and no desire to grub up field flowers and transplant them to town gardens. Neither have they developed that worst sign of perverted taste which we display in mixing our flora and fauna. The Japanese develops with care the flora that he finds in his own land. He does not go about planting exotic bushes in his woods and wastes, as we confuse the aspects of English landscapes by rhododendrons and araucarias. In like manner the monkey, which has long since vanished from England, still exists in Japan ; while the Japanese bird fauna, commemorated by their unapproached art, has added a notable value to the sum of human happiness.

Chapter II Mammals In General; And The Origin Of The British Mammalia

MAMMAL is the most convenient term in English to apply to the members of the class Mammalia, the highest development of living forms on the earth's surface. The word, of course, is derived from the Latin mamma, a teat, and embodies the most obvious distinction between this group and the other vertebrates, because all the Mammalia nourish their young after birth by a liquid developed in glands which are provided with a nipple or teat.1 It must be admitted that at present " mammal " is a somewhat pedantic designation, and is certainly never used by the rustic. But it is difficult to see what other term is to be chosen in preference, if accuracy of speech is desired. <c Animal" applies not only to mammals, but to every other living creature which is not a vegetable. " Quadruped " is equally foolish, because reptiles (and in a sense birds) also possess four limbs which are usually devoted to purposes of locomotion. The old Anglo-Saxon word deor 2 (our English word " deer ") has become restricted to a small group of ruminants, and no longer means all the beasts. The English term which comes nearest

1 Except in the group of the Monotremes, where the liquid of the mammary glands exudes through pores and not through the channel of a nipple. In all the Mammalia except the Monotremes the milk is a sebaceous fluid, but in the case of the Monotremes it would seem to be developed from the sweat.

2 Akin to the German Thier, Latin fera, Greek ther.

MAMMALS IN GENERAL 9

to mammal in comprehensiveness and accuracy is the word " beast," derived through Norman-French from Latin ; but this is somewhat marred by its use as a term of opprobrium among children or its restriction by the agriculturist to horned cattle. Consequently we are obliged to adopt " mammal " as the most correct designation in English for the air-breathing, warm-blooded vertebrates which suckle their newly-born young.

Before beginning a description of British mammals, living or recently extinct, it might assist the unenlightened reader if the author attempted a brief definition of the leading characteristics of the Mammalia as a class. They are warm-blooded, air-breathing vertebrates with a four-chambered heart, with a skin covered usually with hair, wholly or partially ; possessing differentiated teeth l ; lungs freely suspended in the cavity of the chest (partitioned off by a muscular wall from the stomach) ; red blood corpuscles without a nucleus ; and with glands in the skin (usually on the under part of the body) especially developed in the female for the creation of milk as nourishment for the new-born young. They are also marked off from other vertebrates— such as fishes, reptiles, and birds — by the exclusive possession 2 of an outer ear (that is to say, a conch, or flap of skin, muscle, and tendon, which focusses the vibrations of sound on the inner hearing organ) ; by a heart which has only one aortic arch on the left-hand side (not two arches as in reptiles, or one on the right-hand side as in birds) ; by the existence of four optic lobes in the brain for the organs of sight; by a lower jaw of a more fused character, with peculiarities as to its

1 That is to say, teeth not all of one pattern, as in the generality of reptiles, most fishes, and primitive birds, but divided normally into four kinds : incisors for seizing, canine teeth for tearing, premolars for champing, and molars for grinding.

2 The lowest known forms of the Mammalia, the existing Monotremes of Australia, possess no conch, or external ear, but in all other Mammalia where the conch is not present (as in the whales, certain seals, edentates, and insectivores), there is every reason to believe them to be descended from forms possessing the external ear.

composition and articulation with the skull that are essentiallymammalian ; by a skull that lacks several of the many separate pieces of bone that goes to its composition in reptiles and birds. But the last of these obvious distinctions (an invariable one) is the manner in which the skull articulates with the first vertebra of the spinal column. This is by means of two separate processes of bone (the condyles), which develop from the end of the occiput, or roof of the skull ; whereas in birds and most reptiles the articulation of the skull with the vertebral column is by means of a single process of bone. There is a double process— two condyles — in the Amphibians (frogs, newts, etc.), but these condyles do not arise from the bones roofing the skull.

Then, again, the vertebras of the mammalian neck are markedly different in shape and structure from those of the back, and the neck vertebrae are almost invariably seven in number. There are not a few other and minor peculiarities connected with the bones forming the spinal column, with the ribs, the ankle joint, the ear bones, and the soft parts (that is to say, the muscles and the various organs of the body) ; but as this book is not a scientific treatise, it would be wearisome to go too deeply into these particulars. The main feature in the Mammalia which sharply distinguishes them from other animals is the secretion of milk by which the young are nourished after birth. In all the Mammalia, except the two existing forms of Monotreme in Australia ; * the young are born alive. Mammals, therefore, in the eyes of the undiscriminating differ markedly from birds and reptiles, in that they produce their young alive (from eggs so minute that they are scarcely visible to the naked eye). Mammals are not alone in this feature of living-born young. Some fishes and reptiles, extinct and living, have acquired the

1 The echidna and the duckbill — very ancient and primitive types of mammal which present a good many reptilian features — produce eggs with large yolks, and these eggs are either hatched in the mother's pouch, or perhaps in the case of the duckbill, allowed to hatch separately from the mother, after which the young animal is placed in the pouch.

MAMMALS IN GENERAL n

habit of hatching the egg within the mother's body and producing living young.

The mammals probably developed from a group of reptiles generally known as the Anomodonts, and these again arose (in common with the rest of the reptilia) from amphibian forms allied to the extinct Labyrinthodonts. The Anomodont or Theriodont reptiles (remains of which are found all over the world, but principally in North America, Europe, and Africa) differed from other known reptiles in the differentiation of their teeth on mammalian lines ; that is to say, the specialisation of prehensile teeth answering to our incisors, of tusk-like canines, and of molars and premolars that exhibited three or more cusps in the single tooth. The first mammals were creatures allied in their structure to the Monotremes still existing in Australia. From this stock developed what is known as the Eutherian, or true mammalian form. Among the most primitive of the true mammals were the marsupials, who retain many low characteristics coupled with a certain amount of special development and some degeneracy. At the present day marsupials are limited in their distribution to Australia, New Guinea and the southern islands of the Malay Archipelago, and also to North and South America l ; but anciently there were marsupials in Great Britain, creatures somewhat resembling the opossums of America and the banded ant-eater of Australia.

When the earth was passing through the first phase of the Tertiary Epoch (the Eocene period), when in fact the British Islands were beginning to assume something like their present relations with Europe (instead of being an outlying part of North America separated from Europe by a shallow sea), the true mammalia were already spreading out into many orders, a few of which are extinct, but most of which have their living representatives at the present day. These existing orders are (i) the Marsupials ; (2) the Edentates (armadillos, ant-eaters, sloths, etc.) ; (3) the Whales ; (4) the Ungulates (all hoofed mammals) ; (5) the Sirenia (manatis, dugongs, etc.) ; (6) the Carnivores