I. PARASITES OF MAN (part 2 of 2)
Pentastoma constrictum, Von Siebold.--This parasite is at present only known to us in the immature condition; unless, indeed, as is by no means improbable, the adult worm has been described under some other name. It was first discovered by Pruner on two occasions in negroes, and he also subsequently found two specimens of the worm preserved in the Pathological Museum at Bologna, which had been removed from the human liver. Pruner also found it in the giraffe. Bilharz afterwards frequently detected it in the livers of negroes at Cairo. It differs from the larval form of P. tænioides in not possessing integumentary spines; moreover, it is a much larger parasite. The cephalothorax is furnished with four foot-claws, and the elongated abdomen displays twenty-three rings placed at tolerably regular intervals. The anterior part of the animal is obtusely rounded off, the caudal end being conical. The worm usually attains a length of rather more than half an inch, whilst the breadth scarcely exceeds a line.
An extremely interesting account of this worm has been published by Prof. Aitken, accompanied with illustrations by Dr H. C. Gillespie, taken from specimens in the Pathological Museum at Netley. Two cases are recorded. In one of these the encysted worms were found in the liver and lungs, and in the other in the liver only. In Dr Crawford’s account of the post mortem in the last-mentioned case, Prof. Aitken quotes him as saying: “These worms varied in length from an inch to an inch and a half, and were found coiled up like a watch-spring, in small sacs scattered throughout the whole organ.” The patient was a private of the 1st West India Regiment, and died at Bathurst, Gambia, in 1854. In the other case, where the lungs and liver were infested, the patient was an African, about twenty-one years old, who had enlisted into the 5th West India Regiment at Up Park Camp, Jamaica. He had, a few months previously, come from the slave depôt at Rupert’s Valley, St Helena. According to the post-mortem report, furnished by Mr Kearney (staff surgeon), the lower lobe of the right lung contained one or two yellow specks. “When cut into, worms were seen regularly encysted in its substance.” The surface of the liver was dotted over “with about twenty or thirty yellow specks, similar to those seen in the lung.” The longest of these specimens was a trifle less than three quarters of an inch.
Whether Pent. denticulatum be or be not devoid of clinical interest, it is quite clear from Aitken’s account that P. constrictum is a formidable parasite and one that occasionally proves fatal to the bearer. As his remarks suggest, a parasite that can produce both pneumonia and peritonitis is not a creature that either the physician or the sanitarian can afford to ignore. Lastly, I must again express my belief that the so-called Echinorhynchus, described by Welch, if it be not the Pentastoma denticulatum, must either be referred to P. constrictum (in an early larval condition), or to some other hitherto undescribed pentastomatoid larva.
BIBLIOGRAPHY (No. 37).--Aitken, W., “On the occurrence of Pentastoma constrictum in the Human Body as a cause of painful Disease and Death,” repr. from the ‘Science and Practice of Medicine,’ 4th edit., 1865.--Bellingham, in ‘Ann. Nat. Hist.,’ vol. xiv, p. 162.--Blanchard, in ‘Ann. des Sci. Nat.,’ ser. 3, t. viii, and in ‘Règn. Anim.’ (with figs.).--Cobbold, ‘Entoz.,’ p. 393 et seq.--Idem, in ‘Quart. Journ. Med. Sci.,’ 1859, p. 205.--Idem (“P. cephalophi”), in ‘Linn. Trans.,’ xxii, p. 357, and xxiii, p. 350.--Idem, in ‘Zool. Soc. Proc.,’ 1861, p. 124.--Diesing, ‘Syst.,’ i, p. 609.--Idem, ‘Revis. der Cephalocot.,’ s. 327.--Frerichs (l. c., in text), vol. ii, p. 276.--Klob (und Schroff), in ‘Gesellsch. d. Aerzte,’ Wien, 1860.--Küchenmeister, l. c., i, s. 370, Eng. edit., tab. viii.--Idem (with Van Beneden), in ‘Bullet. Acad. Belg.,’ xxii (with figs.), 1855.--Landon (quoted in text).--Leuckart, in ‘Zeitsch. f. rat. Med.,’ 1857; see also “Obs. on the development and early condition of the Pent. tænioides,” in ‘Ann. Nat. Hist.,’ vol. iii, 3rd series, 1859; also my translation of his “Further Observations on the development of P. tænioides,” from ‘Henle and Pfeufer’s Zeitsch.,’ in the ‘Quart. Journ. of Micr. Sci.’ for 1859.--Idem, ‘Bau und Entwicklungsgeschichte der Pentastomen, nach Untersuchungen besonders von P. tænioides und P. denticulatum,’ Leipzig, 1860.--Moquin-Tandon, ‘Med. Zool.’ (Hulme’s edit.), “The Linguatula,” p. 329.--Pruner (“Nematoideum”) in ‘Krankh. d. Orient.,’ 1847.--Schubart, ‘S. und K. Zeitschr.,’ Bd. iv.--Welch, see Bibl. No. 36.--Zenker, in ‘H. und Pf. Zeitschr. f. rat. Med.,’ 1854, s. 212 (with figs.).
The ectoparasitic arachnidans comprise a great variety of mites and ticks (Acaridæ and Ixodidæ) more or less proper to man, and also a number of creatures which, though hardly to be reckoned as human parasites, are apt to transfer themselves from animals to man. Little more than an enumeration of the forms is possible here. The Common Scab or Itch insect (Sarcoptes scabiei) forms the type of a great variety of arachnids, generally spoken of as different species according to the host they dwell upon. Mégnin, however, in his beautiful memoir, quoted below, regards most of the forms of this genus (found on the horse, hog, sheep, dog, wolf, and other animals) as mere varieties. In man the female Acarus burrows beneath the skin, forming galleries or curved channels, in which she deposits her eggs. The irritation produced is not alone due to these excavations, but to the presence also of a poison which the mite discharges when feeding. The Sarcoptes crustosæ of Fürstenberg, producing the Norway itch, is a variety, if, indeed, it can be called as much. Under the frightful name of Dermatophagoides Schérémétewsky two parasites found on an herpetic patient have been described as new to science by M. Bogdanoff, but Mégnin points out that these Acari are only female and young male representatives of his Chorioptes setiferus (var. bovis) respectively. In Newfoundland, Dr Le Roy de Méricourt discovered a singular species upon an officer who had come from Havannah (Tyroglyphus Méricourti, Laboulbène). It possesses enormous palpi, as in the genus Chyletus to which Robin refers it. Another ectozoon, placed by Mégnin and others amongst the lowest types of Arachnida, is the well-known Demodex folliculorum. It is a gregarious species, a dozen or more examples often being present in a single dilated hair follicle. Though disfiguring to the human face it produces little harm. M. Gruby made it out to be a very common parasite, infesting forty out of sixty persons; but Mégnin, in his brochure (l. c. infra, p. 119), shows this statement to be an exaggeration. It infests on the average not more than one in ten persons. According to Gruby, moreover, a single follicle in the dog may contain 200 of these mites, another statement which Mégnin deems unreliable. The Demodex of the dog is only a variety (fig. 53). Many other human Arachnids have been found, some of which appear to be genuine species, whilst others are accidental, so to speak. Of the former kind, perhaps we may reckon the two species discovered by Hessling (Cœlognathus morsitans and Entarsus cancriformis). Of the latter sort, those found by Busk, Simon, and Bory de St Vincent may be cited. The mite found in Simon’s case was the Dermanyssus avium, which infests cage-birds. Probably it was the same species which Bory found on a lady; but in Busk’s negro sailor the mite may have been D. gallinæ of the common fowl. Differing from the mites, proper, and also from the true ticks, are some bug-like forms called Argades. The two best known are the Miana bug of Persia (Argas persicus) and the Chinche of Columbia (A. chinche). Like their congener infesting pigeons (A. reflexus) these parasites are terrible blood-suckers. The bite of the Persian bug is so venomous as to have occasioned death. Various species of tick have been known to attack man, but the species have not been well determined. Although a human form has been described (Ixodes hominis, Koch), yet it is more probable that the species usually attacking man are the same as those known to infest the domesticated animals. In this list we may, therefore, reckon Ixodes nigra, Ix. bovis, Ix. ricinus, and Ix. reduvius. Cases in which one or other of these ticks occasioned much pain and distress are recorded by Hussem, Raspail, and Dr Cosson. Besides these there is a formidable tick well known at Angola (Ix. monbata). Its habits are like those of the common bed-bug. Severe pain comes on two hours after the person is bitten. It likewise attacks animals. The Ix. carapato is similarly troublesome in Brazil. Another very disgusting arachnid liable to attack man is the Galeodes araneoides. This large spider-like creature, two inches in length, commonly attacks camels and has an extremely venomous bite. One or more species of the dung-beetle mites (Gamasidæ) have also been known to fasten themselves on man. According to Latreille, they first get attached to the clothes of travellers, whence they pass to his body, and there shift about, producing great torment. Another disagreeable arachnid is the little harvest bug (Leptus autumnalis), which not only excites irritation during its crawling motion on the human skin, but even succeeds in burying itself near the hairs. The irritation thus produced is almost unbearable. This mite attacks various animals, especially dogs and cats. I myself once suffered severely from this species in consequence of fondling a young wild rabbit which, as I afterwards discovered, was much infested. When the parasites had reached my left arm-pit they occasioned extreme torture. I have known these autumnal spiders to produce small suppurating boils on the abdomen. I may add that Dr Tilbury Fox has brought under my notice an instance where the hexapod larva of another species (probably Trombidium cinereum) was found to have occasioned severe irritation in a child.
BIBLIOGRAPHY (No. 38).--Alibert, ‘Maladies de la Peau,’ Paris, 1833.--Audouin, V., art. “Arachnida,” in ‘Todd’s Cyclop.,’ vol. i, 1836.--Beneden, Van (et Gervais), ‘Zool. Med.,’ 1859.--Bourguignon (et Delafond), in ‘Rec. Vét.,’ 1856.--Idem, in ‘Mém. de l’Institut.,’ 1862.--Cobbold, “Case of Leptus producing Boils,” in ‘Worms,’ p. 140, London, 1872.--Gamgee, ‘Our Domestic Animals in Health and Disease,’ Edin., 1861.--Gerlach, ‘Kraetze und Räude,’ 1857.--Hebra, in ‘Oester. Jahrb.,’ 1864.--Hering, ‘Die Kraetzmilben,’ Stuttgard, 1845.--Krabbe, “Husdyrenes paras. Mider.,” ‘Tidssk. f. Vet.,’ Rœk. 2, Bd. iii.--Küchenmeister, l. c., 1855, s. 412 (good figs.).--Mégnin, ‘Monographie de la tribu des Sarcoptides psoriques.’ (This work contains a full bibliography and numerous beautiful plates; see also Review in the ‘Veterinarian,’ Aug., 1877, p. 563).--Idem, “Mémoire sur un nouveau Symbiote (Chorioptes, Gerv.),” ‘Journ. de l’Anat. et de la Physiol.,’ 1872.--Idem, “Mém. sur un nouvel Acarien,” ibid., 1873.--Idem, “Mém. sur les Hypopes,” ibid., 1874.--Idem, “Mém. sur l’organisation et la distribution zoologique des Acariens de la famille des Gamasidés,” ibid., 1876.--Idem, “Mém. sur les métamorphoses des Acariens en général, et en particulier sur celles des Trombidions,” ‘Ann. des Sci. Nat.,’ 1876.--Idem, “Des conditions de la contagion de la gale des animaux à l’homme,” ‘Arch. générales de Méd.,’ 1876.--Idem, “Mém. sur le Demodex folliculorum (Owen),” ‘Journ. de l’Anat. et de la Physiol.,’ 1877.--Moquin-Tandon, ‘Elém. de Zool. méd.’ (Hulme’s edit., p. 302-328), 1861.--Williams, in his ‘Veterinary Surgery’ (good figs., reproduced from Gamgee’s translation of ‘Gerlach,’ &c.), 1872.
SECTION IV.--PART IV.--CRUSTACEA (Gammaridæ).
Although multitudes of small Crustaceans are parasitic upon fishes, and some few of them adhere to oceanic mammals (Cetacea), I am sceptical as to the parasitism of Crustacea either in or upon man. Many of the Amphipodous Gammari lead a sort of free parasitic existence, and they are themselves very liable to harbor larval parasites. As regards human parasitism from this source the only records known to me are those quoted below.
BIBLIOGRAPHY (No. 39).--Banon, “Freshwater Shrimp, or Gamarus pulex (said to have been passed per anum),” ‘Rep. of Path. Soc. of Dublin,’ in ‘Dub. Med. Press,’ April 6, p. 351, 1864.--Bartels, “Gamarus pulex in the Human Subject, with a postscript by Troschel,” trans. by Dr E. P. Wright, from ‘Verhandl. des Naturhist. verein. der Preuss. Rheinl. und Westph.,’ in ‘Dubl. Med. Press,’ 2nd ser., vol. ix, p. 407, 1864.--Wright, E. P., ‘Remarks on Dr Banon’s Case’ (see Bartels).
SECTION IV.--PART V.--INSECTA (Coleoptera, Diptera, Hemiptera, Aphaniptera).
Whilst very many flies, bugs, lice, and fleas persecute animals, not a few of them also attack man. Several of the species are genuine parasites, others are semi-parasitic, and others, again, are altogether outside the border-land of parasitism in the ordinary sense of the term. In fact, it becomes difficult to say where the line of parasitism should be drawn. I cannot, however, ignore all notice of the insect tormentors, whether strictly parasitic or not.
At least fifty different species have been regarded as playing the rôle of parasitism in man. Amongst the Coleopterous parasites none is more authentic than Blaps mortisaga. At least half a dozen such cases have occurred. Mr Hope’s catalogue of insects producing parasitism in man gives three examples of scolechiasis from this source. Sir J. R. Cormack published a fourth case, and I have recorded a fifth. In this instance I received the living larva from Dr Horne, of Barnsley, who procured it from an infant eleven weeks old. In my ‘Introductory Treatise’ I have alluded to the case of the girl Riordan, who not only passed per anum upwards of 1200 larvæ, but also several perfect insects. The case was first reported by Pickells, Thomson, and Bellingham. One of the other authentic cases, in which only a few larvæ were present, was recorded by Patterson, of Belfast, and the third case by Bateman. Mr Hope’s ‘Catalogue’ originally appeared in the ‘Transactions of the Entomological Society,’ being afterwards published in the pages of the ‘London Medical Gazette,’ 1837. Patterson’s case was also, I believe, first communicated to the Entomological Society.
As regards the mode in which the maggot gained access to the child in Horne’s case, it was not easy to decide; but in the case of the girl Riordan the mode of ingress was sufficiently explained. The Blapsidæ, as a family, are closely allied to the meal-worms, and, like most of the Tenebrionidæ, are black and foul-smelling beetles, frequenting dark and damp situations, from which they escape only at night. The family comprises numerous species, of which probably not more than three are found in this country. They are abundant in Africa, especially in Egypt, where (according to Fabricius, as quoted by Westwood, Figuer, and others) the women eat Blaps sulcata cooked with butter in order to make themselves grow fat. The insects are also employed as specifics against ear-ache and the bite of the scorpion. The superstitious notion of a “charm” is generally at the bottom of these domestic remedies. In the girl Riordan’s case, as Westwood observes (when epitomising Pickell’s account), the parasites, as such, “probably originated in an absurd and superstitious practice, which she had for some time followed, of drinking daily for a certain time a quantity of water mixed with clay, taken from the graves of two Catholic priests, and eating large pieces of chalk. One of these beetles was immersed repeatedly in spirits of wine, but revived after remaining therein all night, and afterwards lived three years.” The intolerance of light shown by the perfect insect seems to be equally shared by the larva. Of this fact I had repeated evidence by observing the behaviour of the living specimen sent to me by Dr Horne. Thus, when, on February 5th, 1877, I placed the maggot on the surface of some moist mould, scarcely half a minute elapsed before it commenced to bore its way downwards, and in less than a minute all but the tip of the tail had disappeared. In like manner, when, on the 7th, I raised the lid of the box, and found the maggot on the surface of the soil, it almost instantly proceeded to bury itself. Hope’s list records no less than nine instances of parasitism in man from the larvæ of Tenebrio molitor, and he gives a score of other Coleopterous insects which he regarded as human “intestinal worms.” Undoubtedly a large number of insect larvæ do get introduced into, and actually live within the human intestines.
Numerous cases of this sort have come under my observation, but it often requires a profound knowledge of entomology to determine the species. Several examples of œstridean larvæ occur amongst them. For one example of Œstrus hominis I am indebted to Mr Higginson, of Liverpool, who obligingly supplied me with notes of the case. Dr Kirk presented me with a small bot which he removed from Livingstone’s leg. I afterwards deposited the African bot, in his name, in the Hunterian collection. Bates speaks of an Œstrus in Brazil producing boils in human flesh. Westwood quotes similar instances. Of these, one was extracted from the thigh by Dr Brick. Mr Doubleday, the entomologist, extracted one from his own leg, and M. Goudot, another entomologist, was also victimised in the same way. Both of these savans were travelling in America at the time. Two cases from South America were also recorded by Howship. In one the larva lodged in the back; in the other in the scrotum. Humboldt noticed that the Indians were much infested by Œstridæ. Three cases are severally recorded by Roulin, Guérin, and Audouin. Mr Stroop also mentions a case in which an Œstrus was removed from an ulcer on the shoulder of a boy in Texas. Another kind of bot known as the Macaco worm (Cuterebra noxialis) occasionally attacks man, but more frequently cattle and dogs. For one example, taken from the leg of a negro, at Belize, British Honduras, I am indebted to Dr Dobson (A. M. D., Netley). Hope’s list records five cases of bots of Œstrus hominus, one of Œ. Guildingii, one of Œ. bovis, and thirteen others (belonging to the same genus) as having been noticed in man. Since his time many additional cases have been recorded by J. M. Duncan and others. In like manner a legion of cases in which the maggots of various Muscidæ have been noticed, either in, upon, or from the human body. At a meeting of the American Academy in April, 1859, Dr Leidy showed some larvæ of the bluebottle fly vomited by a child; five larvæ of the flower-fly (Anthomyia) from a physician’s own person (which had produced choleraic symptoms); and nine examples of Cuterebra noxialis. I have myself encountered numerous insect larvæ in medical practice. Amongst others I have obtained the larvæ of Anthomyia canalicularis in six or eight separate instances. One set of specimens, identified by Wunderlich, was sent to me by Dr Brandt, of Oporto. Drs Duffin, W. Fox, and Leared have supplied me with others. The larvæ described in Farre’s case, not being setose, must be referred to one or other of the Muscidæ proper. Mr Hope gave nearly forty cases of this kind, referable to eight different species of fly, and, as already implied, I have myself collected a great variety of the maggots of Muscidæ passed by the bowel, besides others obtained either from beneath the skin or from open ulcerations.
The flies hitherto noticed as supplying parasitic maggots in man are Musca domestica, M. carnaria, M. larvarum, M. nigra, and perhaps M. Cibaria, M. stabulans, and M. Cæsar. This last, a handsome fly, is the species which proves so troublesome to sheep. The habit which flies have of depositing their eggs in open wounds, when the victims are asleep, is a fertile source of this kind of parasitism. Some of the instances recorded by Kirby and Spence are revolting in the extreme. They quote the cases which came under Mr Sell’s notice in Jamaica. In one instance the flies were hatched in a neglected blister on the chest; in another from the gums and inside of the cheek; and in a third, from the nostrils of a negro, from whom 235 larvæ were expelled. The case of the Lincolnshire pauper, Page, who was literally eaten up by maggots, is almost incredible. An equally horrible instance, however, is recorded by Cloquet. It is said that the Jamaica cases were all due to the larvæ of the bluebottle fly (M. vomitoria). An instance of the same kind has been recorded by Mr Knox (A. M. D.). Sufficiently revolting as these cases are, the horrors attending them are eclipsed by the habits of the larvæ of Lucilia hominivora. The best accounts of its habits are those by M. Coquerel, M. Saint-Pair, and M. Vercammer. The insects lay their eggs in the mouth and nostrils, and when the larvæ escape they devour the tissues surrounding the buccal cavity, the pharynx, glottis, frontal and nasal sinuses, even reaching the sockets of the eye. Several Cayenne convicts have perished from the maggots of this fly, which is also prevalent in Mexico. These are not, however, the only instances of maggots gaining access to the nasal chambers. In a case recorded by Dr Astros, of Aix, 113 were discharged from the nose of a woman; and M. Legrand du Saulle records an instance where a number of larvæ occupied the frontal sinuses of a girl, nine years of age. The larvæ produced persistent headache and convulsions. In the case recorded by Wohlfart, 18 larvæ were discharged from the nose of an old man, and in the example given by Latham several larvæ were obtained from the frontal sinuses of a woman. Bracey Clark also gives an instance in which a bot was taken from a woman’s jaw. Not improbably the well-known Indian disease, termed peenash, or worm in the nose, is due to the presence of Œstridean larvæ. Cases by Rustomjee and Lahory are quoted below. Possibly Stockett’s is another of the same order. The case by Kilgour (Bibliog. No. 34) may be another. I may add that Moquin-Tandon gives an instance of the discharge of seventy-two bots, resembling those of the sheep, from a woman’s nose (‘Journ. de Vandermonde’). The rat-tail maggots or larvæ of Helophilus are parasitic. Two or three instances have been recorded from the horse. I possess one from the human intestine. Kirby also quotes an instance in which Heloph. pendulus was obtained from the stomach of a woman (‘Philos. Mag.,’ vol. ix, p. 366).
A vast number of non-parasitic insects are injurious to man and beast. Inasmuch as they subsist at the expense of their victims and also adhere to his person during their attacks for a shorter or longer time, they, like the leeches, may be spoken of as free parasites. The leg-sticker (Stomoxys calcitrans) penetrates through thick stockings, causing blood to flow freely. The clegg of the West Highlands (Hæmatopota pluvialis) also violently attacks man and beast, especially horses. The mosquito (Culex anxifer), the gnats (C. pipiens, C. annulatus, and C. pulicaris), and the midge (Chironomus plumosus) need only be mentioned. The creeping gnat (Simulium reptans) is also very annoying in Sweden. The rôle of the mosquito, as itself constituting a parasite-bearer, will be again referred to in the closing pages of this work (Book II, Section V). The bites of the tsetse (Glossina morsitans), though so destructive to the horse, ox, sheep, and dog, are not dangerous to man himself. According to Sir S. Baker, the seroot-fly, or zimb of Bruce, which is a species of Pangonia, is excessively annoying to travellers in Abyssinia. Amongst the hemipterous insects the common bug (Acanthia lectularia) is sufficiently blood-thirsty; but there is a far more sanguinary species of this kind in South America. This is the pampas benchucha (Conorhinus nigrovarius). Our distinguished countryman, Darwin, in his ‘Voyage,’ speaking of these wingless insects, says:--“Before sucking they are quite thin, but afterwards become round and bloated with blood. In less than ten minutes the insect is changed from being as flat as a wafer to a globular form.” This insect somewhat resembles our water-scorpion (Nepa cinerea), a non-parasitic species whose bite causes severe pain, as does also the wound inflicted by the water-boatman (Notonecta glauca). There are other species of bug, such as the Acanthia rotundata of Réunion Island and A. ciliata of Kasan, the bites of which are worse than that of the common species. The fly-bugs also, such as the Reduvius personatus, so common in France, and the R. amænus of Borneo and Java, attack man, although their especial habit is to attack and destroy other insects, including bugs themselves. Other species or varieties of Reduvius (R. cruentus, and R. serratus) attack man. The last named is an Indian form, capable, it is said, of producing an electric shock.
Passing to the fleas, the most important and truly parasitic form is the chigoe or gigger (Pulex penetrans). This abounds in tropical America and the West Indies. The female insects only attack man, and this they do for the purpose of securing a lodgment for their offspring. They attack especially the soles of the feet, between the toes and near the nails. In bad cases the whole of the foot becomes affected. After the insect has penetrated the skin its body swells enormously and becomes a mere bag of eggs. This swelling causes active inflammation, which terminates in suppuration and the formation of open ulcers. The chigoe also attacks various animals. In addition to the common flea (P. irritans) other species infesting animals are said to attack man occasionally. As regards those degraded types of insects known as lice I can only afford space to remark that five species have been recognised as human. These are the head-louse (Pediculus capitis); the louse of the eyelids (P. palpebrarum); the clothes-louse (P. vestimenti); the distemper louse (P. tabescentium); and the pubic louse (P. inguinalis). The distress these creatures occasion is only fully known to physicians who deal with the obstinate cutaneous affections caused by their presence (Phthiriasis). Some of the lice found on negroes and Greenlanders are regarded as distinct varieties. Lice are abundant on animals, and some of the species are apt to transfer themselves from one host to another. Thus the Ornithomyia avicularis of cage birds has been found on man, whilst one or more of the numerous species infesting the common fowl are, by transfer, apt to produce a severe phthiriasis in the horse. The lice of the fowl belong to the genera Leipurus, Liotheum, Menopon, Philopterus, Goniodes, and Goniocotes. The unsuitableness of man’s person as a habitation for bird-lice should, however, check the fear which many persons have of handling fresh-killed poultry and game birds. Poultry lousiness in man is probably impossible from this source.
BIBLIOGRAPHY (No. 40).--Arture, “Obs. sur le ver nommé Macaque,” in ‘Mém. Acad. des Sci.,’ Paris, 1753.--Bates, “Œstrus in Man,” ‘The Naturalist on the Amazons.’--Beneden, Van, ‘Animal Parasites and Messmates,’ 1876.--Idem (with Gervais), ‘Traité de Zool. Méd.’--Blood, M., “Case of Larvæ (Musca sarcophaga) expelled alive in the Fæces,” ‘Beale’s Arch. of Med.,’ vol. iii, p. 134, 1862.--Brinton (similar case), ‘Arch. of Med.,’ vol. iii, p. 133, 1862.--Bouyer (quoted by Figuer), ‘Tour du Monde,’ p. 318, 1866.--Clark, Bracey, in ‘Linn. Trans.,’ vol. iii, 1797 (the jaw-case at p. 323), and vol. xv, 1827.--Idem, ‘Essay on Bots,’ 1815.--Cloquet, J., “Case of Blindness from Worms (larvæ of Musca) in the Eyes,” from ‘Arch. Gén. de Méd.,’ in ‘Lancet,’ 1828.--Cobbold, “On Blaps mortisaga as a Human Parasite,” ‘Brit. Med. Journ.,’ 1877, p. 420.--Idem, “Entoz.” (‘Hope’s List.’), p. 416.--Idem, in ‘Worms’ (“Leptus,” &c.), p. 140, 1872.--Coquerel (quoted by Figuer).--Cormack, J. R., “Exhibition of a Larva (B. mortisaga) passed by a Child,” ‘Month. Journ. Med. Sci.,’ vol. i, 1841.--Crumpe, S., “History of a Case in which Worms (larvæ of a beetle) were discharged from the Stomach,” from ‘Trans. of the Roy. Irish Acad.,’ vol. vi, in ‘Med. Facts and Observ.,’ vol. viii, p. 229, 1800.--Denny, ‘Monog. Anoplurorum Brittaniæ,’ 1842.--Duncan, J. M., “On the Occurrence of Bots in the Human Subject,” ‘Edin. Vet. Rev.,’ vol. i, p. 275, 1858-59.--Idem, “The Larva of Œstrus bovis in the Human Subject,” ‘Rep. of Edin. Med.-Chir. Soc.,’ in ‘Month. Journ. of Med. Sci.,’ July, 1854.--Farre, A., “On the Larva of Anthomyia canalicularis,” ‘Micr. Journ. and Struct. Rec.,’ 1841, p. 129, and in ‘Trans. of Micr. Soc. of Lond.,’ orig. ser., p. 51, 1844.--Figuer, in ‘The Insect World’ (good figs.), Janson’s edit., 1869.--Furlonge, “Anat. of Pulex,” in the ‘Journ. of the Queckett Club,’ vol. iii.--Geer, De, ‘Mémoires pour servir à l’Histoire des Insectes,’ 1773.--Gervais (see Van Beneden).--Hill, “Account of the Larva of a supposed Œstrus hominis, or Gad-fly, which deposits its Eggs in the bodies of the human species, with particulars of a Case,” ‘Edin. New. Phil. Journ.,’ vol. xxii, p. 284, 1830.--Hilaire (see St Hilaire).--Hope, “Tables of Cases of (spurious) Intestinal Worms,” ‘Lond. Med. Gaz.,’ 1837-38.--Hoppe, “Case of Larvæ of Insects (Musca stabulans) passed by Stool,” from ‘Bibl. für Läger,’ in ‘Med.-Chir. Rev.,’ 1842.--Hopper, R. S., “Insects (Stratiomis) voided with Urine,” edit. note in ‘Micr. Journ. and Struct. Rev.,’ p. 160, 1841.--Joly, ‘Recherches sur les Œstrides en général,’ &c., Lyons, 1846.--Keferstein, ‘Sur l’Oistros,’ Isis, 1827.--Kirby (and Spence), ‘Introd. to Entomology,’ 7th edit., 1856.--Knox, M., “Maggots, the larvæ of the Bluebottle Fly, in Syphilitic Ulceration of the Throat,” ‘Lancet,’ Oct. 6, 1877, p. 514.--Lahory, B. T. C., “On Peenash, or Worms in the Nose,” ‘Ind. Ann. of Med. Sci.,’ 1855, and ‘Edin. Med. Journ.,’ 1857.--Leach, “Œstridæ,” in ‘Wernerian Trans.,’ 1817.--Leidy, in ‘Proc. Phil. Acad. Nat. Sci.,’ 1859, p. 7.--Maclean, “On the Oistros,” ‘Linn. Trans.,’ vol. xiv, 1824, and in ‘Zool. Journ.,’ vol. i and iv.--Metaxa, “Vom Œstrus (u. s. w.),” in ‘Neuen Nord. Beitr.,’ Bd. i, and in ‘Mém. de Zool. Med.,’ Rome, 1835 (quoted by Westwood).--Moquin-Tandon, ‘Med. Zool.’ (l. c., Bibl. No. 38).--Newport, art. “Insecta,” ‘Todd’s Cyclop.,’ 1839.--Rustomjee, B., “Case of Worms in the Nose, or ‘Peenash,’” in ‘App. to Bomb. Med. and Phys. Soc. Trans.,’ No. vii, new ser., p. 21, 1861; see also Lahory, on ‘Peenash.’--Saint-Hilaire, “Sur l’Œstre chez l’homme,” in ‘Ann. Soc. Ent. de France,’ 1833.--Say, “Brick’s Case,” in ‘Trans. Acad. Nat. Sci. Phil.,’ vol. ii.--Sells, in ‘Trans. Entom. Soc. Lond.;’ see also Lemprière’s ‘Diseases of the Army in Jamaica,’ vol. ii.--Stockett, T. H., “An account of a Headache cured by the discharge of a Worm (?) from the Nose,” ‘Med. Com.,’ vol. xix, p. 157, 1794, and in ‘Trans. Coll. of Phys. Phil.,’ vol. i, part i, p. 181, 1793.--Stroop, St J., “Œstrus,” in ‘Amer. Naturalist,’ vol. vii, p. 437.--Tanner, “On Lice,” in his ‘Pract. of Med.,’ vol. ii, p. 429, 6th edit., 1869.--Westwood, in his ‘Classification of Insects,’ vol. ii, 1840.--Wohlfart (quoted by Moquin-Tandon).--Yule, “Case of Larvæ of Insects in the Human Stomach,” ‘Edin. Phil. Journ.,’ and ‘Lond. Med. Repos.,’ 1825.
SECTION IV.--PART VI.--PROTOZOA (Psorospermiæ, Gregarinidæ, &c.).
The scope of this work does not demand that I should comprise within its limits any vegetable parasites; nevertheless, I must needs refer, however briefly, to certain confervoid and sarcodic organisms, which, for the most part, lie on the borderland of the animal and vegetable kingdoms. Professor Cohn regards the bacteria as allied to the Oscillitoriaceæ. He puts them in his order Schizosporeæ. It is of little moment, practically, where these protista forms are placed. Unquestionably many of them are parasitic, as they live in the tissues, fluids, and secretions of animal bodies, including man. Their presence in cattle is associated with an anthracoid disease (charbon), whilst in the human body they have been detected in connection with zymotic affections. They have been found by Cohn, Sanderson, Klebs, Chauveau, and others, either in the lymph of vaccine pustules, or in the miliary eruptions of typhus fever. Professor Beale, who was one of the first to observe these special organic particles in vaccine lymph, denies that they are true Bacteria; and, indeed, he warmly disputes the inferences that have generally been drawn from the fact of the presence of such particles in lymph, blood, and other nutrient fluids. The best known and defined forms are Bacterium termo and Bact. lineola, which are concerned in the production of putrefaction, Bacillus anthracis, found in the blood of animals suffering from carbuncular disease, Micrococcus septicus, found in typhus and pyæmia, M. vaccinæ of cow pox lymph, and M. diphthericus, in diphtheria. As regards their prevalence in certain forms of relapsing fever, Sanderson states that Dr H. V. Carter, of Bombay, examined the blood of 250 fever patients and found spirilla in nearly every instance. From the independent observations of Pasteur, Sanderson, Lister, Tyndall, Bastian, Eberth, Roberts, Davaine, and many others, it seems clear that the Bacteria and their allies play an important part in association with certain morbid states. However, as regards the etiology of the maladies in which these organisms are found, it is perhaps too early to speak with absolute confidence. The subject cannot be dealt with here; moreover, it is outside the range of my personal investigations.
Passing to those protozoa which, although retaining some vegetable affinities, are more or less distinctively animal, I notice the obscure organisms termed psorosperms. In dealing with these I shall treat of the forms that infest both man and animals, confining my remarks to such as happen to have come under my own observation.
In the year 1865 the public were thoroughly roused to a sense of danger arising from the consumption of meat. The panic originated with the outbreaks of trichiniasis in Germany. During the excitement which subsequently prevailed at the time of the rinderpest, all sorts of erroneous notions took possession of the popular mind, and the errors were stimulated by writers ignorant of helminthology. In January, 1866, I published a few observations, the purport of which was to show that certain microscopic organisms found in animals dying from cattle plague were harmless “parasitic Protozoa,” possessing more or less striking vegetable affinities. About a week previously some interesting researches on these so-called cattle-plague bodies had been published by Dr Beale. Those who first saw these bodies thought they had stumbled upon organisms new to science. I showed that similar or analogous organisms were to be met with in a great variety of animals, and likewise in the human body. They had been called worm-nodules, worm-nests, egg-sacs, eggs of the common fluke, young “measles,” corpuscles produced by muscular degeneration, psorospermiæ, stages of growth of gregarinæ, amœboid bodies, and so forth. In so far as the higher animals were concerned, Dujardin was the first to describe them. He found these organisms in a mole. This animal, however, having been fed upon earth-worms known to harbour such parasites, there was no difficulty in accounting for the source of the psorosperms.
In 1853 Hessling discovered psorospermial sacs in the muscular substance of the heart, not only of the ox, but also of the sheep and roe. By him they were regarded as evidences of muscular degeneration. About ten years previously Miescher found similar bodies in the muscles of the mouse.
In 1857 Rainey described similar structures taken from the flesh of swine; and, in his memoir, he went so far as to maintain that these bodies were early stages of development of the common pork-measle. In the year 1858 Gubler wrote an important paper on this subject, in which he related a case where twenty cysts existed in the human liver. The cysts were of great size, mostly as large as a hen’s egg, one of them being some six inches in diameter. Naturally, the largest had been diagnosed as an ordinary hydatid. However, on evacuating their contents (post mortem), they were found to harbor enormous quantities of minute corpuscles strictly analogous to those usually obtained from psorospermial sacs. Gubler believed he had stumbled upon masses of eggs of Distoma hepaticum, but in this he erred. Shortly after Gubler’s discovery similar bodies from the human liver were described by Virchow; and in 1862, the subject was followed up by Dr Dressler, of Prague. Dressler found in the human liver a number of pea-shaped bodies, the milky contents (breisubstanz) of which displayed a multitude of the characteristic corpuscular elements referred to. These particles, already considered as equivalent to, if not identical with, the so-called pseudo-navicellæ of gregarinæ, were soon encountered by a variety of independent observers. Thus, Leuckart noticed these bodies in various animals; but with caution remarked:--“Concerning the nature of these formations I will not decide. To be candid, however, it appears to me to be in no way made out whether the psorospermiæ are to be considered as the result of a special animal development, whether they, like pseudo-navicellæ, are the nuclei of gregariniform productions, or whether they are the final products of pathological metamorphosis.” Leuckart found these organisms in the intestines of a trichinised dog, also in a sheep and pig fed with Trichinæ. He also found them in the muscles of another pig fed with psorosperms, and likewise in the liver of various rabbits. He remarks that in swine these parasites are more abundant than measles. They were present in five of eighteen pigs, and also in two out of four sheep, whose flesh was especially examined. The observations of Lindemann at Nischney-Novgorod are particularly interesting. This medical officer discovered psorospermial sacs attached to the hair of a girl who was being treated in hospital for chlorosis. The sacs in question bore close resemblance to the bodies which we found in abundance in diseased and healthy cattle. It would further appear, from Lindemann’s observations, that the affection is not very uncommon amongst the Russian peasants.
In connection with and attached to the same parasitically affected hairs Lindemann also noticed several movable gregarinæ; and partly from this circumstance he was led to believe in the existence of a genetic relation subsisting between the two kinds of bodies. He further expressed his conviction that the people contracted the disease by washing themselves with water in which gregarinæ abounded. Lindemann moreover refers to Lebert as having noticed similar parasites in a case of favus, and concludes that these organisms are of a vegetable nature. His opinion, though not shared by the majority of parasitologists, is nevertheless supported by the views of Robin, Leydig, and others. Of still higher interest are the observations of Lindemann respecting the occurrence of psorospermiæ in the capsule of the kidney of a hospital patient who died with Bright’s disease. The sacs in this case were remarkably small; nevertheless their corpuscular contents indicated their true nature. The pseudo-navicellæ measured only 1/5000″ in diameter. Amongst other contributions of interest I may refer to those of Dufour, J. Müller, Creplin, Kölliker, Keferstein, Stein, Drummond, Lieberkühn, and E. Ray Lankester. I doubt if the vegetable organisms described by Prof. W. T. Gairdner can be referred to this group of parasites. At all events, by whatever name these spurious entozoa are called, they were first discovered by Dufour in insects, by Müller in fishes, by Miescher in the mouse, by Dujardin in the mole, by Hessling in the larger quadrupeds, and by Gubler in man. The results of my own examinations may be briefly re-stated. In the flesh of cattle I found psorospermial sacs varying from 1/120″ to 1/12″ in length, and in that of sheep from 1/220″ to 1/80″. The bodies were enclosed in well-defined transparent envelopes, and their contents exhibited indications of segmentation. In some specimens the segments displayed themselves as a complete cell-formation, the contents of each cell being uniformly granular. Under the 1/4″ objective the contained granules were clearly visible, and on rupturing the sac their peculiar characters were at once manifest, each granule or corpuscle represented a pseudo-navicel, all displaying a tolerably uniform size, averaging 1/2000″ in diameter. Some of the corpuscles were round, others oval, several bluntly pointed at one end, many curved and fusiform, not a few being almost reniform. Highly refracting points or nucleoli were visible in their anterior.
Turning to the practical aspect of the subject, I remarked that these bodies had nothing to do with the cattle plague. No one who carefully examined the flesh of animals that had died of rinderpest had failed to discover them; yet, in one or two instances they appear to have escaped notice. When it is considered how long it takes us to examine a few grains weight of muscle carefully, it is obvious that the body of a large beast might contain many hundreds of these organisms without our being able to detect their presence, except by a prolonged investigation. In the few rinderpest beasts, portions of whose flesh I submitted to the microscope, I should say there were not more than 100 of these bodies in one ounce of meat; but in the heart of a healthy sheep (which I afterwards ate) I calculated there were about 1000 parasites to the ounce, and in the heart of a healthy bullock (which likewise served me for a meal) their numbers were rather in excess of those in the sheep. Altogether, at two meals, I could not have swallowed less than 18,000 of these psorosperms. Consumers of beef, mutton, and pork eat these bodies every day, but they take no harm because the parasites in question are not true helminths. Fine healthy beef has been returned to the butcher when it was as good as any other meat in the market. I have examined various kinds of meat, such as veal, pork, and mutton, but in none have I found so great an abundance of psorosperms as in beef, which was, notwithstanding, perfectly healthy and sound. I calculated that in one instance a single ounce of the flesh contained upwards of 2000 parasites. There is practically no limit to the extent of this kind of parasitism, and there is no organ of the body in which psorosperms may not be found. Moreover, the forms they display are exceedingly various. Psorosperms have been found by Siedamagrotzky in the muscles of the horse, and not very long ago, through the help of Professors Simonds and Axe, I had the opportunity to examine some peculiar worm-like structures which occupied the mitral valve of a horse. To the naked eye they looked like coiled nematodes, but I was soon convinced that they formed a peculiar type of psorosperm. A complete view of these bodies was a matter of great difficulty owing to the delicate nature of their limiting membrane and to the confusion of markings produced by the interlacing of the fibres of the chordæ tendinea. At length, by spreading a portion of the membrane of the valve over a large glass slide, and by allowing it to dry slowly, I found that the vermiform body presented neither beginning nor end. The appearances were curious and puzzling. The organism formed a flattened tube or sac, almost uniform in width and variously twisted upon itself. From the main tube there projected several hernia-like secondary loops or branches, most of them presenting less than half of the thickness of the former. These peculiarities, however, can hardly be understood without reference to the original illustrations. That these secondary coils were not of the nature of hernial protrusions was evident, not alone from the nature of their contents, but also from the fact that they showed distinct anastomoses. In fact, the parasite was a simple sac or bag with branches.
On puncturing the main tube with a fine needle a small quantity of tenacious creamy fluid made its escape. This, under Ross’s 1/4-inch lens, resolved itself into a few excessively delicate sarcode globules surrounded by fine granules. The granular matter displayed a tendency to collect itself in the form of oval masses without showing any trace of a limiting border. One of these masses, measuring 1/250″ in length, I examined under a Wasserlein-objective, when I further ascertained that the elementary particles or granules were uniformly oval in shape, rather highly refractive, their size scarcely exceeding 1/8000″ in diameter. The sarcode corpuscles, on the other hand, were of different sizes, ranging between 1/3000″ and 1/1600″ in diameter.
From the facts thus elicited, negative as they were in respect of helminthic structure, I could see no escape from the conclusion that we had to deal with a new form of psorospermial bag, whose granular contents consisted of excessively minute pseudo-navicellæ. In the centre of the largest hernia-like loop there was a clear oval disk, which at first brought to my mind the nucleus of Monocystis infesting the earth-worm, but it was merely a vacuole.
The case recorded by Gubler reminds me of another remarkable instance of psorospermial cysts, in this case associated with true hydatids. In 1873 Dr Whittell sent me particulars of a case in which the contents of an hydatid of the liver (drawn off, during life) consisted of shreds of a true hydatid, a few echinococcus-hooklets, together with multitudes of spindle-shaped amœboid particles of excessive minuteness and delicacy. The bodies, floating in a transparent fluid, formed a thick milky or creamy fluid, resembling pus in appearance; but there was no trace of pyæmia. Judging from Dr Whittell’s figures, he must also have found a solitary microscopic nematoid hæmatozoon, the nature of which was not clear to him. I believe it to have been a specimen of Filaria sanguinis hominis. Be that as it may, the case is altogether unique and deserves further elucidation.
As regards the higher forms of protozoa it must suffice to allude to the Cercomonas hominis of Davaine, found in the dejections of cholera patients, to the Cerc. urinarius of Hassal and C. saltans of Ehrenberg, to the Trichomonas vaginalis of Donné, detected in the vaginal mucus, and to the Balantidium coli of Claparède and Lachmann, originally found by Malmsten in the human colon. The Balantidium, or Paramæcium coli, has frequently been observed in the evacuations of fever patients, and it has also been found by Dr Treille in patients suffering from the Cochin-China diarrhœa. Monads have also been found in the stomach and intestines of the hog and various other animals. Infusorial parasites are particularly abundant in batrachians, the Bursariæ of frogs and toads being familiar to every helminthologist.
BIBLIOGRAPHY (No. 41).--Arloing (and Tripier), in ‘Gaz.-hebd.,’ 1873, p. 574 (quoted by Davaine).--Balbiani, ‘Compt. Rend. Soc. Biol.,’ 1867, p. 103 (quoted by Davaine and Bastian).--Bastian, “On the Nature of the so-called Sarcina ventriculi,” ‘Brit. Med. Journ.,’ Feb. 3, 1872.--Idem, “On Heterogenesis in its relation to certain Parasitic Diseases,” ‘Brit. Med. Journ.,’ Feb. 24 and April 20, 1872 (see part iv, p. 417, with figs. from Balbiani).--Beale, L., “Entozoon-like bodies in Muscles,” in the ‘Microscope in Medicine,’ 4th edit., p. 485, 1878.--Idem, “Bacterium Hypothesis of Contagium,” ibid., pp. 313-321.--Burnett, W. T., “On Psorospermia, Mermithes, &c.,” in a paper entitled ‘Reviews and Records in Anat. and Physiol.,’ in ‘Amer. Journ. of Sci. and Arts,’ vol. xviii, 2nd ser., p. 104, 1854.--Carter, H. V., “On Spirilla,” quoted by Sanderson in ‘Brit. Med. Journ.,’ Nov. 17, 1877, p. 700.--Cobbold, “Remarks on Spurious Entozoa found in Diseased and Healthy Cattle,” ‘Path. Soc. Trans.,’ vol. xvii, p. 452, 1866, and ‘Lancet,’ Jan. 27, 1866, p. 88; see also Prof. J. Gamgee’s work on the ‘Cattle Plague.’--Idem, “On Worm-like Organisms in the Mitral Valve of a Horse,” ‘Veterinarian,’ Sept., 1877.--Idem, “On Psorospermiæ in the Eye of the Cod (Morrhua),” ‘Linnean Society’s Proc.,’ May, 1862, and in ‘Intellectual Observer,’ 1862, p. 199.--Cohn, ‘Nova Acta,’ xxiv, s. 103 (quoted by Leuckart), Bd. i, s. 139.--Creplin, ‘Wiegmann’s Archiv,’ 1842, s. 61.--Davaine, l. c., 2nd edit., “Synops. xxi” (with bibliog. refs.), 1878.--Donné, ‘Cours de Microscopie,’ Paris, 1847, p. 157.--Dressler, quoted by Leuckart, Bd. i, s. 141.--Drummond, ‘Edin. Phys. Rep.,’ 1852,--Dufour, ‘Ann. des Sci. Nat.,’ 1837.--Dujardin, ‘Traité’ (l. c., see Bibl. No. 1).--Eberth, ‘Zur Kentniss Bacteritischer Mykosen,’ 1872.--Eimer, ‘Ueber Psorospermien,’ 1870.--Gairdner, ‘Edin. Phys. Soc. Rep.,’ 1853.--Gluge, “Cysts in Sticklebacks,” ‘Bullet. Acad. Roy. des Sci. de Bruxelles,’ 1838.--Gubler, ‘Mem. Soc. Biol.,’ 1859, p. 657, and in ‘Gaz. Méd.,’ 1858, p. 61.--Harz, C. O., “Eine neue Mikrococcusform im lebenden Thierkörper,” ‘Deutsche Zeitschrift für Thier-Medicin und vergleichende Pathologie,’ f. Novemb., 1878.--Hessling, ‘Sieb. u. Köll. Zeitsch.,’ 1853, p. 196.--Henle, ‘Müller’s Archiv,’ 1845.--Hollis, W. A., “What is a Bacterium?” repr. in the ‘Veterinarian,’ p. 205, 1875.--Keferstein, ‘Götling. gelehrte Anzeigen,’ 1862.--Kloss, ‘Ueber Parasiten (u. s. w.)’ (quoted by Davaine).--Knoch, ‘Journ. de Russ. Kriegs. dep.,’ Bd. xcv, 1866 (quoted by Leuckart and by Davaine).--Kölliker, in ‘Zeitsch.’ (by Sieb. and Köll.), 1848-49.--Lambl, ‘Prager Vierteljahrschrift,’ 1859.--Lankester, E. R., “Recent Researches on Bacteria (with copious references),” ‘Quart. Journ. Micr. Science,’ Oct., 1878.--Lebert, ‘Phys. Pathologique’ (quoted by Leuckart).--Leidy, “Gregarina,” ‘Amer. Phil. Trans.,’ 1851.--Leisering, “Bericht (u. s. w.),” in ‘Sachsen,’ 1865.--Leuckart, l. c., Bd. i, s. 135 and 740, and Bd. ii, s. 842 et seq.--Leydig, ‘Müller’s Archiv,’ 1851, s. 221, in ‘Micr. Journ.,’ 1853, p. 206, and in ‘Arch. f. Anat. und Phys.,’ 1863, s. 191.--Lieberkühn, ‘Müller’s Arch.,’ 1854.--Lindemann, ‘Bullet. Soc. imp. des Naturalistes de Moscow,’ 1863, and in ‘Gaz. Méd. de Paris,’ 1870, p. 86.--Lister, J., “Natural History of Bacteria,” ‘Micr. Journ.,’ Oct, 1873.--Malmsten, “Paramæcium coli” (quoted by Davaine, l. c., 2nd edit., p. 67).--Miescher (quoted by Leuckart and Siebold).--Müller, ‘Archiv,’ 1841, s. 477.--Rainey, ‘Phil. Trans.,’ 1857.--Rayer, “Singulière éruption sur un véron (Cyprinus),” ‘Arch. de Méd. Comparée,’ Paris, 1842 (quoted by Davaine).--Rivolta, “Psorospermi, &c.,” trans. in ‘Journ. des Vét. du Midi,’ 1869, pp. 445 and 521.--Robin, ‘Les Végét. Paras.,’ 2nd edit., p. 291.--Sanderson, in ‘Privy Council Reports,’ 1874.--Siedamagrotzky, in ‘Recueil de Méd. Vét.,’ 1872, p. 460.--Stein, in ‘Müller’s Arch.,’ 1848, and ‘Ann. Nat. Hist.,’ 1850.--Idem, “Abhandl. d. k. Böhmischen Gesellsch.,” x, s. 69, oder Lotos, 1859, s. 57 (quoted by Leuckart, Bd. i, s. 151).--Steinberg, ‘Walter’s Zeitschr. f. die moderne Medicin,’ 1862, and in Leuckart, Bd. ii, s. 844.--Stieda, ‘Arch. f. pathol. anat.,’ Bd. xxxv, and in Leuckart, Bd. ii, s. 846.--Suriray, “Sur quelques parasites du lombric,” ‘Ann. des. Sci. Nat.,’ 1836.--Virchow, “Zur Keutniss der Wurmknoten,” ‘Arch. f. Anat. u. Phys.,’ xviii, s. 523.--Vogel, ‘Path. Anat.,’ i, s. 404.--Waldenburg, “Psorospermien,” in ‘Arch. f. Path. Anat.,’ s. 435, 1867.--Windbladh, also Wising, ‘On Balantidium coli’ (quoted by Leuckart, Bd. ii, s. 846-847).--Winkler (see Leisering).
APPENDIX.--On various occasions I have dwelt upon the necessity of acquiring accurate information respecting the degree of mortality due to parasites, and in the present volume (p. 124) I have referred to the defective evidences supplied by the returns of the Registrar-General in respect of the echinococcus disease. My object is not to cast blame upon those whose duty it is to publish the returns, but rather to call attention to the advantages that would follow if the Registrar-General were supplied with full and accurate information on this head.
Through the courtesy of Mr Noel A. Humphreys I have been furnished with the following official statement of the number of Deaths from Worms in England and Wales, as recorded in the Annual Reports of the Registrar-General throughout a decade of years:
+--------------+----+----+----+----+----+----+----+----+----+----+ | |1868|1869|1870|1871|1872|1873|1874|1875|1876|1877| +--------------+----+----+----+----+----+----+----+----+----+----+ |Total | 172| 148| 151| 160| 154| 183| 188| 227| 204| 225| | including-- +----+----+----+----+----+----+----+----+----+----+ |Porrigo | 15 | 13 | 9 | 9 | 9 | 14 | 5 | 16 | 7 | 13 | |Scabies | 6 | 2 | 7 | 1 | 4 | 2 | -- | 5 | 2 | 3 | |Tapeworm | 8 | 3 | 6 | 3 | 5 | 3 | 5 | 5 | 2 | 6 | |Hydatids | 20 | 20 | 33 | 37 | 41 | 34 | 29 | 43 | 31 | 51 | +--------------+----+----+----+----+----+----+----+----+----+----+
Considering the prodigious advances in helminthology during the last half century, it is certainly remarkable that under the category of “worms,” as a cause of death, only two kinds of true helminths should be mentioned in the Registrar’s record. It will also strike the experienced hospital and dispensary physician as somewhat remarkable that of the two death-producing parasites above named one of them should be the “tapeworm.” Now death from Tænia is certainly a very rare occurrence, although grave nervous symptoms are not unfrequently due to its presence in man. Thus, I am inclined to regard the 46 reported instances of death from this cause as a redundant estimate. On the other hand, I am surprised to see no specified instances of death from lumbricoid Ascarides, from Oxyurides, or even from Cysticerci, which now and then take up their residence in the human brain.
As regards hydatids I believe the returns to be excessively deficient. In place of an average of 34 deaths annually from this cause in the United Kingdom I am of opinion that at least 400 deaths are due to hydatids. This opinion and the data on which it was founded were communicated by me twelve years ago to the Linnean Society, and I have since become acquainted with facts which lead me to conclude that my original estimate was very much below the mark. The post-mortem registrar of one of our large hospitals has told me that of late years as many as ten deaths might be reckoned as annually due to hydatids in their institution alone. At a smaller hospital I ascertained that the average was about four. Obviously, if these estimates are correct, the Registrar-General’s returns for the United Kingdom do not record a tithe of the annual mortality due to hydatids. Perhaps another half century will elapse before the truth of my deductions be confirmed by the official returns. For me, it must suffice to have pointed to the desirability of securing more accurate records.
By a curious coincidence I had only just sent to press the sheet of this work recording the statistics of hydatid disease in Australia (p. 123), when a paper dealing with the same subject appeared in the ‘Lancet.’ I refer to the brief memoir of Dr David Thomas, of Adelaide, South Australia, which was published on the 1st of March, 1879. Dr Thomas writes as follows:
“It is well known that Australia presents an extraordinary prevalence of hydatid disease, but, as far as I know, no definite statistics have been published to illustrate the fact. Consequently, some months ago, with the kind assistance of the Hon. W. Morgan, the present Chief Secretary of South Australia, I endeavoured to procure reports from the Governments of Victoria, New South Wales, Queensland, New Zealand, Tasmania, and Western Australia, upon this question. Unfortunately, the mode of registration of the causes of death in most of these colonies was such as prevented the necessary replies being supplied. However, it appears that in Tasmania no deaths were returned from this disease in the ten years 1867-77. During the greater part of the same period no separate classification of hydatid disease had been adopted in New South Wales; but in 1875 four deaths were attributed to hydatids; in 1876, eleven were so returned. In Victoria, however, the record of deaths from this cause is far more complete, and I append a table based upon the returns from that colony.
“One case, in which hydatid of the kidney was present, accompanied by malignant disease of bladder, with stricture, was not returned as a case of hydatid causing death.
“During the decade 1867-77, 2·5 per 1000 deaths were due to hydatid disease. In 183 out of the 307 cases the liver was either solely or conjointly with other organs the seat of disease. Holding the second place in frequency come the lungs in 71 cases, i.e. 53 simple and 18 complicated.”
Table of Deaths returned as being due to Hydatid Disease in the Province of Victoria during the ten years 1867-77.
Key to Column Headings:
A = Year. I = Omentum. B = Liver. J = Ovary. C = Lungs and pleura. K = Womb.(?) D = Brain and spinal cord. L = Abdominal cavity. E = Heart and pericardium. M = Situation not recorded. F = Kidney. N = More than one organ invaded. G = Spleen. O = Total annual deaths. H = Pancreas. P = Totals
+----+---+--+--+--+--+--+--+--+--+--+--+--+-------+----------+ | A | B | C| D| E| F| G| H| I| J| K| L| M| N | O | +----+---+--+--+--+--+--+--+--+--+--+--+--+-------+----------+ |1868| 17| 5| | 1| | | | | | | 2| 7| 1(a)| 33 | |1869| 6| 8| 1| | | | 1| | | | 2| 1| 3(b)| 22 | |1870| 10| 2| 1| | | | | | | | | 4| | 17 | |1871| 4| 6| 1| | | 1| | | | 1| | 1| 1(c)| 15 | |1872| 19| 3| 1| 1| | | | | | | 2| 2| 1(d)| 29 | |1873| 17| 3| 2| | | | | | | | | 2| 5(e)| 29 | |1874| 21|10| 1| | | | 1| | | | | 6| 2(f)| 41 | |1875| 29| 7| | 2| | 1| | | 1| | 3| 2| 2(g)| 47 | |1876| 23| 1| | | 2| | | | | | 1| 4| 5(h)| 36 | |1877| 20| 8| | 1| | 1| | 1| | | 3| 2| 2(i)| 38 | +----+---+--+--+--+--+--+--+--+--+--+--+--+-------+----------+ | P |166|53| 7| 5| 2| 3| 2| 1| 1|1?|13|31|22 | 307 | | | | | | | | | | | | | | | |in 10 yrs.| +----+---+--+--+--+--+--+--+--+--+--+--+--+-------+----------+ |(a) Lungs and kidneys. | |(b) In two instances liver and lungs; in the third case | | liver and brain. | |(c) Lungs and liver. | |(d) Lungs and abdominal cavity. | |(e) In three cases liver and lungs; in one kidney and | | abdomen; in another liver, lungs, omentum | |(f) Liver and lungs. | |(g) One liver and lungs; the second case lungs and heart. | |(h) Three cases liver and lungs; one liver and kidney. | |(i) Liver and lungs. | +------------------------------------------------------------+
Such are the returns as recorded by Dr Thomas. If a comparison be instituted between the data supplied by his decade-report and those supplied by the decade-report which I have previously adduced (p. 123), it will be seen that as regards the returns for the years 1868-72, inclusive, both reports are in perfect agreement. Of still more interest also is the circumstance that whilst, on the one hand, out of the total of 307 deaths given in Dr Thomas’s table, 116 occurred during the first semi-decade (i.e. from 1868 to 1872, inclusive), on the other hand, no less than 181 deaths occurred during the second semi-decade (i.e. from 1873 to 1877, inclusive). This increase of 45 deaths during the later semi-decade is very significant. It points either to the fact of more careful returns having been made, or to an actual increase in the fatality of the disorder. Possibly both the causes alluded to operated to affect the returns. Be that as it may, Dr Thomas’s record is highly instructive, and should stimulate the profession in England to supply our Registrar-General with more precise data wherewith to construct his annual reports.
II. PARASITES OF ANIMALS
In dealing with this division of the subject it will be impossible to give more than the faintest outline. Let it be borne in mind that quite as much information might be offered by me respecting the parasitism of each of the commoner domestic animals as has been already advanced in regard to the helminthism of man. That would by no means exhaust the subject. Thus treated, a score of volumes, each equal in size to this, would barely suffice to cover the whole ground of Parasitology; and yet there are not wanting intelligent persons who regard Helminthology as unworthy of their attention. These persons form a far too prevalent type of educated ignorance, and unfortunately, it is just this class of people who enjoy the prerogative of educational responsibility. Even our metropolitan scientific institutions, expressly raised for the purpose of diffusing useful knowledge, shrink from the revelations of parasitism. Dominated by the miserable conception which judges that the life-history of a worm cannot prove either interesting or instructive to their audiences, they let slip the acquisition of scientific data, a knowledge of which might enable them to combat successfully some of the most terrible evils to which human flesh, in common with that of animals, is heir.
In the following few pages many new points of departure for fresh scientific work will inevitably be suggested; and if I only succeed in conveying to the working student an adequate grasp of the whole subject, especially in its bearings on the welfare of the higher domesticated animals and man, I shall have accomplished all that I can reasonably hope to do within the restricted limits of space at my command.
SECTION I (MAMMALIA).
In dealing with this class of hosts, exclusive of man, I shall notice the entozoa of the various orders successively, taking the arrangement which I employed many years since when writing the Mammalian Division of a popular treatise called the ‘Museum of Natural History.’ The internal parasites of those orders which happen to embrace important domesticated animals will necessarily receive more attention than the others; some notice of the ectozoa being likewise added.
I. QUADRUMANA (Monkeys)
Monkeys are less afflicted with flukes than most animals. The species known to me are Distoma laciniatum, found by Brongniart in the pancreas of Simia maimon; D. orbiculare and Amphistoma emarginatum, from the intestines of Cebus trivirgatus; and Bilharzia hæmatobia, a single specimen of which I obtained from Cercopithecus fuliginosus. The monkeys of the Old World rarely harbor full-grown tapeworms, but Cysticerci are abundant (Cyst. tenuicollis, C. cellulosa, C. pileatus, C. crispus). The common hydatid (Echinococcus polymorphus) has been found in many of the Simiæ, and by myself in a Madagascar lemur (L. macaco). Dr Leidy also obtained three hydatid cysts from a large monkey. On the last day of the year 1857 I obtained some polycephalous hydatids (Cœnurus lemuris) from a ring-tailed lemur. They infested the liver, being more abundant in the lungs. They occupied both sides of the chest. Loose and detached specimens also existed in the cavity of the right pleura. Most of those occupying the chest were connected to the pleura, forming vesicular, semi-transparent masses, varying in size from a filbert to a large walnut, many being united in bundles of much larger size. One of these masses is here drawn (1, fig. 54). It consists of four large Cœnuri, their combined pedicles forming a single stalk. A fifth hour-glass-shaped rudimentary Cœnurus is also visible. Every Cœnurus supports a variable number of lobules, each lobe supporting one or more papillæ. Here and there the papillæ resemble chains of beads. No trace of tapeworm heads could be seen, but under a half-inch objective glass, I found some flat papillæ presenting oval depressions at the surface (2, fig. 54). On examining some of the larger papillæ they were found to consist of membranous layers folded one within the other. These were carefully dissected and examined with the aid of needles, when each one showed in the centre a well-formed tapeworm head with four characteristic suckers, and a prominent rostellum supporting a double coronet of hooks, thirty-two of the latter in all (3, fig. 54). The hooks displayed a marked disparity of size and form. Each hook showed conspicuous anterior and posterior root-processes, the larger set of hooks individually measuring about 1/225″ and the smaller 1/330″ in length (4, fig. 54). There were numerous calcareous corpuscles. The interior of each vesicle was filled with a fluid, in which there were no free scolices. On referring to my notes I find that the lemur had arrived in England about four months previously.
Larval cestodes do not appear to be common in the monkeys of the New World (Cebidæ), nevertheless I found several Cysticerci in the liver of Macacus radiatus (Feb. 19th 1857), and a single specimen in the sooty monkey (Dec. 4th 1857). They were wrongly described by me as Cercariæ. The Cebidæ are largely infested with tapeworms (Tænia megastoma and T. rugosa). A species of Ligula (L. reptans) has likewise been found beneath the skin of Callithrix sciureus and in one of the marmosets (Hapale melanurus). Perhaps the most common helminth infesting monkeys is the nematode called Filaria gracilis. I have examined specimens from the orang, the capuchin, and the spider monkey. This parasite commonly occupies the abdomen, coiled beneath the peritoneum, or within folds of the mesentery. It sometimes occurs beneath the skin, or within the connective tissue of superficial muscles. The female worm has been known to reach a length of five feet. In 1873 Mr Samuel Smith, of Clifton, sent me five specimens of this worm. From one of the males, which measured twenty inches in length, I procured some spermatozoa, and found their long diameter to average 1/1400″. These corpuscles and other structures, as well as the worm itself, are figured in my ‘Notes on Entozoa’ quoted below. Next in frequency, perhaps, is the whipworm (Trichocephalus dispar), which monkeys of all kinds harbor in common with man. Besides these nematodes, Physaloptera dilatata is found in the stomach of American monkeys, and Ascaris distans also (in the large intestine of marmosets more particularly). This Ascaris has also been found in Cercopithecus fuliginosus and in Simia sabæa. A small spiroptera is said to infest the walls of the stomach of Simia maimon. To Dr Murie I am indebted for a large roundworm (Ascaris lumbricoides) taken from the intestine of a chimpanzee (Troglodytes niger), and also for a smaller nematode taken from a green mona-monkey (Cercopithecus). This I have described and named Ascaris cuspidata. From the intestines of a chacma (Cynocephalus porcarius) M. Schafhert procured sixteen examples of a small strongyle (Str. attenuatus, Leidy).
The singular monkey known as Tarsius spectrum is liable to be attacked by a filaria (F. lævis), which is found beneath the skin. At least two species of Echinorhynchus (E. spirula and E. elegans) are known to infest monkeys. I have carefully examined and figured E. elegans in the ‘Zoological Society’s Proceedings,’ from specimens supplied to me by Dr Murie. They had been obtained from a pinche monkey (Hapale œdipus) from New Granada. I am under the impression that Diesing’s original description of this parasite is the only one that exists. I have gone over his numerous memoirs contributed to the Vienna Academy, but can find nothing beyond the specific characters given in his ‘Systema.’ All the specimens in the Vienna Museum, whence his description is taken, were collected by Natterer. They were procured from the marakina (Midas rosalia), from two other true marmosets (Hapale ursula and H. chrysoleuca), and from a squirrel monkey or tee-tee (Callithrix sciureus). In the monkey which died at the Zoological Society’s Gardens the cause of death was not clearly due to the parasites; nevertheless, the mucous layer of the intestine, to which the entozoa were attached, showed deep conical pits or depressions at the spots where the worms had anchored themselves. During the perfect retraction of the proboscis of this Echinorhynchus the centre is represented by a wide opening which communicates with a cavity beneath. The end of the neck thus forms a sort of collar, or rosette, made up of rays arranged like the spokes of a wheel. When the proboscis is exserted this collar is more or less convex, but it becomes slightly concave when the proboscis is retracted. Diesing recognised twenty-four rays; they probably vary from that number up to twenty-eight, at least I counted twenty-seven in my specimens. During exsertion the proboscis forms a nipple-like projection. According to Diesing it supports three rows of hooks, but I certainly saw four rows. When separately magnified these hooks present very different appearances as to size and contour. These variations I believe to be due to growth. The largest hooks measured about 1/200″ in length.
As regards insect parasites, it is well known that monkeys are largely infested by fleas, but the species have not been much studied. The same may be said of their mites (Acaridæ). A species of Pentastoma (P. tornatum, Creplin) has been found occupying little cysts of the peritoneum and omentum in Simia maimon and S. cynomulgus. Under a synonym (Linguatula Diesingii) it has been very fully described by Van Beneden. Another species (P. subcylindricum) has been found attached to the lungs and liver of a marmoset (Hapale chrysopygus). Dr Leidy found five specimens of P. euryzonum in cysts on the subperitoneal surface of the liver of Cynocephalus porcarius. Leuckart believes that Dr George Harley’s P. polyzonum is the adult state of P. euryzonum, and that P. subcylindricum is the larva of P. proboscideum, found in Boa constrictor and other serpents.
BIBLIOGRAPHY (No. 42).--Beneden (see Van Beneden).--Cobbold, “On Filaria gracilis and Ascaris cuspidata,” in ‘Zool. Soc. Proc.,’ Feb. 3, 1874, p. 124.--Idem, “List of Entozoa, including Pentastomes, obtained from Animals dying at the Menagerie in 1857-60 inclusive,” ‘Proc. Zool. Soc.,’ 1861.--Idem, ‘Entozoa,’ p. 119.--Idem, “On Parasite-Larvæ (Cœnurus and Echinococcus of the Lemur),” ‘Intell. Observer,’ vol. iii, pp. 86-96.--Idem, “Bilharzia from Cercopithecus,” in ‘Synops. of Distomidæ,’ ‘Proc. Linn. Soc.,’ 1860, Zool. Div., pt. v, p. 31, and in “Parasites from Zool. Gardens.,” in ‘Intell. Obs.,’ June, 1862, p. 352.--Idem, “On Echinorh. elegans,” ‘Proc. Zool. Soc.,’ 1876, in ‘Notes on Entozoa,’ pt. iii, plate xvi, p. 202.--Creplin, “On P. tornatum,” ‘Troschel’s Arch.,’ 1849, s. 54.--Idem, “F. gracilis,” in ‘Wiegm. Arch.,’ 1851, s. 270.--Diesing, ‘Syst.,’ l. c., s. 611, and in ‘Sitzb. d. k. Akad.,’ 1854, s. 598.--Harley, G., in ‘Proc. Zool. Soc.,’ 1857, p. 12.--Leidy, J., “On Pentastoma,” ‘Proc. Phil. Acad. Nat. Sci.,’ 1850, p. 97.--Idem, ‘Hydatids,’ l. c., 1856, p. 46.--Idem, ‘Strong. atten.,’ l. c., p. 54.--Leuckart, ‘Bau und Entwicklungsgeschichte der Pentastomen,’ 1860, “P. polyzonum,” ‘Synops.,’ s. 153.--Molin, “On F. gracilis,” in ‘Sitzungsb. d. k. Akad. d. Wissensch.,’ 1858, Bd. xxviii, s. 376.--Schneider, ‘Monag. der Nem.,’ 1866, “F. gracilis,” s. 87.--Smith, S., “On F. gracilis found in connection with the Great Omentum of a Spider-monkey,” ‘Proc. of Bristol Naturalists’ Soc.,’ vol. i, 1873.--Van Beneden, “Ling. Diesingii,” in ‘Mém. Acad. Belgique,’ vol. xxiii, ‘Recherches sur l’organisation et le dévélopment des Linguatules, suivies de la description d’une espèce nouvelle provenant d’un Mandrill,’ 1849.
II. (CHEIROPTERA)
Until lately not very much attention had been paid to the parasites of bats, probably on account of the insignificance of the hosts. However, whilst Dr Dobson has recently been extending the subject of Cheiropterology, Prof. van Beneden has added largely to our knowledge of the parasites of bats. In his beautiful memoir, the Belgian helminthologist asks whether the parasites quit their hosts during the period of hybernation, and then proceeds to answer that question in the negative. Should the bats die, the parasites of necessity share the same fate. It would appear, however, that the spermatozoa of the worms are capable of surviving their parents for a fortnight or even longer. Flukes abound; the most common species (Distoma lima) infesting the pipistrelle, noctule, mouse-colored bat, Natterer’s bat, parti-colored bat, Daubenton’s bat, whiskered bat, and the greater and lesser horseshoe bats. Almost as abundant is the Distoma chilostomum found in most of these bats, and also in Leisler’s or the hairy-armed bat. Dujardin’s D. heteroporum is a synonym of the species. Schreber’s Monostomum is probably identical with Van Beneden’s Distoma ascidia. This fluke he found in Vespertilio marinus, V. dasycnemus, V. Daubentonii, V. emarginatus, V. serotinus, V. mystacinus, V. pipistrellus, V. auritus, and in Rhinolophus hippocrepis. Another species, distinguished from D. ascidia by its large ventral sucker, has been found in great numbers in the noctule (D. ascidioïdes, Van Beneden). The cestodes of bats are not numerous. The best known species (Tænia obtusata) has been found in the serotine, in the mouse-colored bat, and in Vespertilio lasiurus. Another species (T. decipiens) occurs in Molossus perotis, and Chylonycteris rubiginosus, and a scolex, forming the type of a new genus and species (Milina grisea, Van Ben.) has been obtained by hundreds in the intestines of Vesp. murinus and V. serotinus. Of nematodes we have Ophiostomum mucronatum, Rud., and Oph. spinosum, W.-Suhm (from Vespertilio mystacinus)., Trichosomum speciosum, Van Ben., Strongylus tipula, Van Ben., Strongylacantha glycyrrhiza, Van Ben., Litosoma filaria, Van Ben., Ascarops minuta, Van Ben., and one or two sexually-immature forms, either found loose in the tissues or occupying cysts. The Acanthocephala are not known to infest bats. Respecting insects, one family (Nycteribiidæ) is exclusively parasitic upon bats. They resemble the forest-flies in their habits. The best known species is Nycteribia Latreillei, but several others (N. biarticulata and N. Sykesii, Westw.) have been described. One or more of the Brazilian bats are infested by Lipoptena phyllostomatis, Nitsch, and Westwood has obtained several allied forms of Hipposcidæ (of the genus Strebla), also from bats. As regards the true Arachnidans (mites and ticks), Van Beneden enumerates Ixodes lividus, Van Ben., Pteroptus vespertilionis and P. arcuatus, Koch, Otonissus aurantiacus and Cerathophyllus octactenus, both of Kolenati, and Caris elliptica.
BIBLIOGRAPHY (No. 43).--Audouin, ‘Ann. des Sci. Nat.,’ xxv.--Beneden, P. J. van, “Les Parasites des Chauves-souris de Belgique,” fr. vol. xl of the ‘Mém. de l’Acad.,’ 1873.--Diesing, ‘Syst. Helm.,’ ii, p. 530.--Dufour, ‘Ann. des Sci. Nat.,’ 1831.--Dujardin, l. c., p. 437.--Kolenati, ‘Die Parasiten der Chiropteren,’ 1857.--Latreille, art. “Nycteribie,” in ‘Nouv. Dict. d’Inst. nat.’--Müller, ‘Zool. Danica,’ ii, p. 43, “Fasciola vesp. (syn. Dist. lima).”--Perty, “Lipoptena,” ‘Del. an. art. Brasil’ (quoted by Westwood).--Rudolphi, ‘Synops.,’ p. 117.--Westwood, “Mém.,” in ‘Zool. Soc. Trans.,’ 1835.--Idem, ‘Modern Classif. of Insects,’ vol. ii, p. 585, 1840.--Willemoes-Suhm, R. V., “Helminthologische Notizen,” iii, ‘Zeitsch. f. wiss. Zool.,’ 1873.
III. (INSECTIVORA)
The entozoa of insectivorous mammals, though sufficiently numerous, are not important practically. The common hedgehog (Erinaceus europæus) is infested by four flukes (Distoma pusillum, D. trigonocephalum, D. caudatum, D. linguæforme), and also by three thorn-headed worms (Echinorhynchus napæformis, E. amphipachus, and E. major). Two tapeworms are also known (Tænia compacta and T. tripunctata). More attention has been paid to the round worms. A species of strongyle (S. striatus) infests the lungs, the male being readily distinguished by its nearly round hood. A second species of strongyle has been mentioned by Diesing, but it is more than doubtful. The lungs are also infested by a small trichosome (Eucoleus tenuis of Dujardin); another species of the genus (Trich. exiguum) infesting the stomach and small intestine. As the Trichina spiralis has been repeatedly reared by myself and others in the hedgehog, the little flesh-worm must also be noticed in this place. Physaloptera clausa occupies the stomach, and a minute Ascaris (A. pusilla) is found in cysts of the peritoneum. According to Wedl, the intestine of the Egyptian hedgehog (Erinaceus auritus) is infested by another worm, which he calls Pterygodermatitis plagiostoma. This is allied to Froelich’s genus Rictularia. As regards the mole (Talpa europæa), two flukes have been described (Distomum flexuosum and Monostomum ocreatum), also two round worms, namely, Ascaris incisa, occupying the peritoneum, and Spiroptera strumosa in the cavity of the stomach. Dr Schneider places the latter with the Filariæ. A little tapeworm (Tænia bacillaris) infests the small intestines, and a larval cestode occupies the liver and subcutaneous connective tissues. This is the well-known Cysticercus talpæ, which Leuckart and others have referred to as being the scolex or juvenile state of Tænia tenuicollis infesting weasles (Mustelidæ). The Cysticercus is also found in Arvicola arvalis. In regard to the shrews, many species of fluke have been described as occupying the intestines. In Sorex araneus and S. leucodon, the Distoma migrans; in S. constrictus, the D. exasperatum; in S. tetragonurus, the D. corrugatum and D. rubens; the last-named fluke, with two others (D. instabile and D. truncatum), being also found in Daubenton’s shrew. The tapeworms are numerous--Tænia neglecta, T. furcata, T. uncinata, T. pistillum, T. tiara, T. scalaris, T. scutigera. With the exception of the last named, all these forms occur in the common shrew. According to the investigations of M. Villot the cysticercal stage of T. pistillum is to be found in the glow-worm (Glomeris). This scolex (Staphylocystis micracanthus, Villot) multiplies by proliferation, and in this way the swallowing of a single intermediate host may result in the formation of a hundred or more tapeworms. Another species of Staphylocystis (S. biliarius) is considered by Villot to be the larval source of T. scutigera and T. scalaris, which are perhaps identical species. A small Echinorhynchus (E. appendiculatus), found in the intestines and also encysted in the mesentery of the shrew, in like manner becomes transferred to the stomach of the fox. The nematodes of shrews possess little interest. In the common shrew the only species known are Trichosoma splenaceum and an immature worm, whilst in Sorex tetragonurus we have T. incrassatum, occupying the tunica vaginalis of the testis, and Strongylus depressus in the intestines. Not many other insectivora appear to have been studied in relation to their internal parasites. A larval cestode has been noticed in the Russian musk rat (Mygale), and also a tapeworm (Tænia sphærocephala) in the golden mole (Chrysochloris). Several flukes and a tapeworm have been found in the water-shrews (Sorex fodiens), but, so far as I am aware, nothing has been done in connection with the parasites of the Macroscelidinæ, of the Banxrangs (Tupainæ), or of the Tanecs (Centites) and their allies. The entozoa of the star-nosed and shrew moles of North America (Condylura and Scalops) also deserve attention. From the last-named genus (S. canadensis) Prof. Leidy obtained a single male spiroptera. It occupied the stomach and was only half an inch in length.
BIBLIOGRAPHY (No. 44).--Leidy, “S. scalopsis canadensis,” ‘Proc. Phil. Acad.,’ 1851, p. 156.--Linstow, “D. cordatum, Einige neue Distomen (u. s. w.),” ‘Arch. für Anat.,’ 1873, s. 95.--Molin, ‘Una Monografia del genere Physaloptera,’ Wien, 1860 (p. 7, “P. clausa,” and p. 31, “P. limbata”).--Idem, ‘Nuovi myzelmintha,’ Wien, 1859, p. 10, Spec. No. 8.--Idem, ‘Una Monogr. del genere Spiroptera,’ Wien, 1860, p. 25, Spec. No. 22.--Schneider, ‘Monogr. der Nematoden,’ Berlin, 1866, s. 103, Spec. No. 39.--Stieda, in ‘Troschel’s Archiv,’ 1862, “Description and figs. of Tænia uncinata and T. furcata of the Shrew.”--Thomson, art. “Ovum,” in ‘Todd’s Cyclop. of Anat. and Phys.,’ contains figs. and description of T. pistillum (from Dujardin), vol. v, p. 28.--Villot, A., “On the Migrations and Metamorphoses of the Tapeworms of the Shrews,” in ‘Ann. of Nat. Hist.,’ March, 1878, from ‘Comptes Rendus,’ Nov. 19, 1877, p. 971.--Wedl, K., “Zur Helminthenfauna Ægyptens,” ‘Sitzungsb. d. math.-naturw. Classe’ (u. s. w.), Bd. xliv, Abth. i, s. 464.
IV. (CARNIVORA)
Notwithstanding the importance of the entozoa of this large section of mammals, I must deal with them very summarily, emphasising my remarks on the parasites of the dog and cat. Only a few of the ectozoa can be noticed.
The bears are much infested by nematodes, the species being Ascaris transfuga and Spiroptera (Gongylonema) contorta of Molin. The latter is found in the œsophagus. Immature round worms have also been found in cysts. These were erroneously described as cestodes by Zeder and Gmelin. The bear, however, is very liable to be infested by genuine Cysticerci. Retzius found them in the muscles, and they are described as examples of the ordinary hog-measle. The museum attached to Guy’s Hospital contains the heart of a bear which is largely infested by Cysticerci. A species of tapeworm has been found in the polar bear. The coati (Nasua narica) is infested by Ascaris brachyoptera in the intestine, by Molin’s Physaloptera semilanceolata from the stomach, by Echinorhynchus spirula, Tænia crassipora, and Ligula reptans, the latter occupying the muscles. A second species of Ascaris (A. alienata) is described from Nasua rufa.
The racoons (Procyon) are infested by a species of pentastome (P. subcylindricum), and Prof. Leidy has described a threadworm (Filaria insignis) obtained from a cyst in the foot. The gluttons (Gulo) are liable to be infested by an Ascaris, a Ligula, and by Eustrongylus gigas. The giant strongyle also infests the coati (Nasua). The skunk harbors Tænia crassipora. The Hunterian Museum contains four specimens of Strongylus cruciformis taken from a badger (Meles). The otters are largely infested by flukes; Distoma trigonocephalum, D. incrassatum, and D. rude being found in Lutra vulgaris, L. solitaria, and L. braziliensis, respectively, the latter also harboring Hemistoma clathratum. Otters are likewise infested by Ligulæ and Eustrongyli. The weasels (Mustelidæ) are attacked by a legion of entozoa, comprising flukes, tapeworms, round worms, and thorn-headed worms; they are also liable to harbor many ectozoa, a large tick (Ixodes) being especially troublesome.
Amongst the nematodes is Van Beneden’s Filaroides mustelarum, for specimens of which I am indebted to Mr Wright Wilson. This is found in the lungs, trachea, and in the frontal and nasal sinuses of the common marten (Mustela foina), in which situations it causes absorption of the cranial bones. This worm occurs also in the polecat (M. putorius), in the common weasel (M. vulgaris), and in the pine-marten (M. martes). The larvæ reside in frogs. Weasels are also very liable to have their kidneys invaded by Eustrongylus gigas. A species of Ascaris and a Trichosoma (T. entomelas) are not uncommon in the intestines. In regard to the tapeworms, Tænia tenuicollis infests the polecat and the common weasel, and T. intermedia the pine-marten. The most common fluke of the weasel is Distoma trigonocephalum. This infests the intestine, while D. megastomum is found in the stomach. The stoat or ermine (M. erminea) harbors Strongylus patens and Tænia brevicollis.
The parasites of the civets, ichneumons and their allies, (Viverridæ) are of little importance. Many years ago I described a small fluke (Distoma compactum) obtained from the lungs of the common Indian ichneumon (Viverra mungos). It is figured in my ‘Entozoa,’ (p. 16). Two species of tapeworm (Tænia platydera and T. genettæ) have been found in the common genet (V. genettæ), and also a round worm (Ascaris brachyoptera). From another viverra (V. senegalensis) Dujardin obtained a strongyloid worm (Dochmius crassus). A species of mongoos (Herpestes leucurus) is likewise infested by tapeworms (Bothriocephalus folium).
Comparatively speaking, very few entozoa infest the hyænas. In this family I include the earth-wolf (Proteles lalandi). Some years back Prof. Flower sent me a large number of delicate nematodes found loose in the peritoneal cavity of this singular South African carnivore. The worms themselves were so peculiar that I was compelled to form a new genus for their reception (Acanthocheilonema dracunculoides). From the intestines of the common Hyæna striata Dr Lautner obtained Echinorhynchus gigas.
The parasites of the wolf, jackal, and fox family (Canidæ) have especial interest, as including those of the dog. I can, however, do little more than mention the names of the various helminths of the dog, and the sources whence they come. At the same time, I shall incidentally refer to the wild canine animals that happen to harbor the same parasites.
The flukes of the dog are few in number. Perhaps the most important is Distoma conjunctum, originally discovered by myself in an American fox (Canis fulvus) that died at the Zoological Gardens. Lewis, eleven years afterwards, found it in the pariah dogs of India, where it is of frequent occurrence. It infests the bile ducts. As already stated, Prof. McConnell subsequently found this entozoon in man (1875), a second instance being recorded later on (1878). Another species of canine liver fluke has been described by Prof. Ercolani (D. campanulatum), besides which there is the winged species occupying the small intestines (Holostoma alatum). This latter is also found in Canis azaræ.
The tapeworms of the dog are not only numerous, but also particularly injurious, alike to their bearers and to mankind. By experimental research we have ascertained the sources of most of the Tæniæ. The serrated species (T. serrata) is derived from Cysticercus pisiformis infesting hares and rabbits. This is common in sporting animals, owing to the careless practice of allowing gamekeepers and kennel masters to throw the fresh viscera of the intermediate hosts to the dogs. I have witnessed this stupid habit in the field. The cucumerine tapeworm (T. cucumerina) is, by most observers, considered to be identical with the T. elliptica of the cat. I regard it as a variety. This delicate species is excessively common and is now, through Melnikow’s discovery, known to be derived from the louse of the dog (Trichodectes latus). This circumstance affords a curious illustration of the fact that an ultimate host may carry the intermediate host upon its back.
As regards the relative prevalence of these tapeworms in England, it may be said that whilst T. serrata occurs almost entirely in our harriers, greyhounds, sheep-dogs, and lurchers (taught to “pick up” hares), the T. cucumerina is liable to infest any variety of dog, and probably infests nearly 70 per cent. According to Krabbe the prevalence of the last-named species is 57 per cent. in Iceland and 48 per cent. in Copenhagen, whereas the T. serrata is almost absent from those countries. The gid tapeworm (T. cœnurus) is derived from the ordinary gid hydatid infesting the brains of sheep and lambs. The polycephalous bladder-worm (Cœnurus cerebralis), so familiar to agriculturists and veterinarians, is often confounded with the ordinary hydatid infesting ruminants. Cœnuri infest the soft parts of rabbits, but it remains to be shown whether they are the same species. Possibly the Cœnurus cuniculi is merely a variety. The gid tapeworm is not very abundant in England. In Denmark it appears to be rare, occurring in 1 per cent. only; but in Iceland Krabbe found it in 18 per cent. In common with other helminthologists, I have frequently reared this and the serrated species by worm feedings administered to dogs. The lettered tapeworm (T. litterata) is very commonly spoken of as the Tænia canis lagopodis. It was so named by Viborg, but I prefer the more distinctive nomenclature of Batsch. We know nothing, for certain, respecting the source of this entozoon. It is rare if not altogether wanting in Denmark, but abundant in Iceland (21 per cent.). I have obtained specimens from a cheetah (Canis jubatus) which died at the Zoological Gardens, and Mr W. H. Jackson, of Oxford, found it in a cat. The worm is certainly not confined to the Arctic fox (C. lagopus.).
A well-known tapeworm infests the fox which has not yet been noticed in the dog. This is the Tænia crassiceps, whose scolices (Cysticercus longicollis) reside in the viscera and soft parts of field mice and voles (Arvicola arvalis, A. terrestris, A. amphibius). This relationship was pointed out by Leuckart. Another tapeworm (T. opuntioides) mentioned by Rudolphi as occurring in the wolf, seems to be of doubtful authenticity. A formidable and not uncommon tapeworm is Tænia marginata. This large species occurs in at least 25 per cent. of English dogs, whilst in Iceland its prevalence reaches 75 per cent. In Denmark about 14 per cent. only.
It is well known that the larval or scolex stage (Cysticercus tenuicollis) of the margined tapeworm resides in the sheep and dog. In a feeding experiment with five examples of this bladder worm I reared five strobiles of ten days’ growth. These immature tapeworms were each one inch long. By far the most important tapeworm of the dog, however, is the hydatid-forming species (T. echinococcus). This remarkable entozoon is the sole cause of the terrible echinococcus disease, so prevalent in Iceland and elsewhere. Experimental research, initiated by von Siebold, has explained its origin; Van Beneden, Zenker, and others have also experimented successfully. Rarely attaining a length of 1/3″, the perfect strobile is made up of only three proglottides in addition to the head, the lowermost segment being sexually mature. As hydatids (Echinococcus veterinorum or E. hominis) are found in a great variety of animals as well as in man, and as these bearers form so many kinds of intermediate hosts, it is easy to understand how readily dogs and wolves may acquire the sexually-mature tapeworm. I am in possession of hydatids from the liver of a clouded tiger (Felis macroscelis). In England the Tænia echinococcus is excessively rare, and has not been seen in any dog which had not previously been subjected to a feeding experiment. Mr Nettleship succeeded in rearing large numbers. In Iceland, Krabbe found dogs to be infested to the extent of 28 per cent., a proportion fully explaining the prevalence of hydatid disease in that country. The remaining tapeworms of the dog belong to the genus Bothriocephalus; of these, the broad tapeworm (B. latus) is best known, because it infests man. Diesing has described a variety found in the Pomeranian dog as a separate species (Dibothrium serratum). The museum of the Royal Veterinary College contains a very perfect specimen of B. latus from an English dog, but the parasite is of rare occurrence in this country. It is generally supposed that this tapeworm is derived from the consumption of fish belonging to the salmon and trout family, but Dr Fock, of Utrecht, thinks that the bleak (Leuciscus alburnus) is the usual intermediate host. I have already discussed this question at some length. Experimental proof is still wanting. In addition to B. latus the dog is liable to harbor B. cordatus, B. fuscus, and also two varieties of the last-named species (B. dubius and B. reticulatus, Krabbe). Taking the pit-headed tapeworms as a whole, their prevalence in Iceland is not considerable, amounting to about 5 per cent. only. Lastly, it may be mentioned that instances are recorded of the occurrence of the hog-measle (Cysticercus cellulosæ) in the dog. Though many have felt sceptical on this point, Gurlt’s authority is not to be lightly set aside, confirmed, as it has been, I believe, by MM. Mégnin and Leblanc.
Passing to the round worms it may be said that Ascaris marginata is, at the best, a mere variety of A. mystax of the cat, with which must also be placed A. leptoptera of the lion and other felines. The lateral appendages not only vary in breadth in these three forms, but also in the specimens obtained from each host. I have encountered examples in a dog, which measured more than six inches in length. The worm is excessively common in England, occurring in probably not less than 75 per cent., whilst in Denmark it occurs in about 24 per cent. According to Krabbe it is rare in Iceland. Its presence is at all times more or less injurious to the bearer, being a frequent cause of sickness, colic, convulsive fits, and paralysis. Occasionally the worms prove fatal to dogs by wandering into the trachea. At the Royal Veterinary College, in 1864, a litter of six puppies, of only three weeks growth, died rather suddenly in consequence of the presence of these worms in the stomach and small intestines. So far back as the year 1684 Redi described round worms from the walls of the œsophagus of a dog. These were afterwards noticed by various observers in tumours of the mucous membrane of the stomach. Owing to their red color, derived from the ingested blood of the host, the species was named Spiroptera sanguinolenta. In 1867 I suggested that the minute Filariæ found by Grube and Delafond in the blood of dogs would probably turn out to be referable to this species. The researches of Lewis have proved that this supposition was correct. To be sure, other nematoid hæmatozoa, of microscopic dimensions, occur in the dog, but those described by Grube and Delafond may be referred to Spiroptera. These authors estimated their number in the canine host to vary from 11,000 to upwards of 200,000. In one instance Messrs Grube and Delafond found six worms lodged in a clot occupying the right ventricle of the heart. Four were females and two males. Although they were described as representing an altogether new species, which they termed Filaria papillosa hæmatica canis domestici, I think there can be little doubt that they were examples of Spiroptera sanguinolenta not fully grown. The writings of Lewis abound with interesting details respecting the structure and development of this worm, and as much may be said of the writings of Manson and Welch concerning the cruel threadworm (Filaria immitis, Leidy) occupying the right cavities of the heart. I was first made acquainted with this entozoon in 1853, by examining specimens in the possession of Prof. Hughes Bennett of Edinburgh; at which time also I was put in possession of a valuable MS. (since lost) describing the ravages of this entozoon in the dogs of China. I have since received numerous verminiferous hearts both from China and Japan, and also some heart-worms from Charleston, U. S., sent by Mr M’Innes. In a recent communication, Dr Manson has spoken of this worm as if it were comparatively harmless, but all the evidence I long ago received through the late Mr Swinhoe, formerly H. B. M. Consul at Amoy, through Mr Dare’s letters enclosing Dr Orton’s valuable observations (addressed to the editor of the ‘Field’), through the lost MS. above alluded to, through Dr Lamprey’s statements, and through many other sources, lead to the very opposite conclusion. No doubt the canine hosts do for a time appear to be little inconvenienced by their nematode guests, but sooner or later the most distressing symptoms set in. As in Hoysted’s case (quoted below) the convulsive spasms may occasion death in a few minutes, but frequently they last for hours or days, with more or less prolonged intervals of relief before the final struggle.
Some other filariform nematodes have been imperfectly described. Of these, Gescheidt’s Filaria oculi canini (F. trispinulosa, Diesing) was probably a sexually-immature worm, and the same may be said of the encysted worms found by Mr Mather in the mucous coat of the intestines and in the liver ducts and acini (Filaria hepatica, Cobbold). Of more interest is Leisering’s hæmatozoon (Strongylus subulatus). These minute worms occupy the veins, the largest females not exceeding 1/12″ in length. They are viviparous, and thus form another source of embryonic hæmatozoa. A single drop of infected venous blood commonly carries from four to six mature worms. In this place may be mentioned Dr Osler’s Strongylus canis bronchialis. The largest males measure 1/6″ and the females fully 1/4″. In the worms sent to me by Prof. Osler I saw no evidence of strongyloid structure, and in his description he avoids all mention of the presence of any caudal hood in the male. I regard the worms as Filariæ (F. Osleri, Cobbold). Very great interest attaches to them from the fact that they produce a destructive canine epizoöty, resembling the ordinary “husk” or parasitic bronchitis of calves, lambs, and other domesticated animals. The only other genuine strongyle known to infest the dog is Eustrongylus gigas. This is a very common parasite in wolves. I have already spoken of this parasite at some length (Book I, p. 207), and can only further refer to the recently published case by Mégnin (quoted below, and at full length in my paper in the ‘Veterinarian’ for April, 1879). The Museum of the Royal Veterinary College contains three fine examples of this worm coiled within the kidney of a dog, or rather within the renal capsule, for the substance of the organ is almost entirely wanting. These are from Bickford’s case.
Amongst the many good “finds” made by Lewis in India, not the least interesting is that appertaining to Cheiracanthus robustus. Lewis, indeed, supposed that he had detected Echinorhynchi in chestnut-sized tumours of the walls of the stomach, but, as I pointed out at the time, the parasites were entirely destitute of Acanthocephalous structure. As is well known, this curious nematode infests various felines, such as the wild cat, puma, and tiger. In addition to the above canine nematodes we have the wrinkled threadworm (Trichosoma plica) infesting the bladder. This is of much more frequent occurrence in the fox. In the list Trichina spiralis must also be included, although, so far as I am aware, it has only been seen in dogs that have been subjected to feeding experiments.
Another nematode common to the fox and dogs, and infesting the cæcum, is the whipworm (Trichocephalus depressiusculus). It is very rare in the dog. Lastly, there is the important little strongyloid worm generally known as Dochmius trigonocephalus. At the hands of Leuckart the general structure and development of this entozoon have received complete elucidation. It infests the small intestines, and is found alike in the fox, wolf, and cheetah. It has also been obtained from Canis lagopus and C. azaræ. Dr Krabbe did not encounter this worm in Icelandic dogs; nevertheless, he obtained it in a blue fox which died in Kjoerbolling’s menagerie, and which had come from Iceland. In Danish dogs it occurred in less than 2 per cent. The embryos of this worm are rhabditiform and possess three long bristle-like teeth, the slender tail being furnished with a distinct appendage at the tip. They develop in moist situations, where they feed freely, grow rapidly, and change their skins, throwing off the caudal tip with the first month. It seems evident that they do not require a change of hosts, since Leuckart succeeded in rearing the sexually-mature Dochmii by introducing the rhabditiform larvæ into the stomach of the dog; moreover, his experiments upon water-snails belonging to the genus Physa gave negative results.
Of Arachnidan parasites (Trachearia) infesting the dog, by far the most interesting is the well-known Pentastoma tænioides, shown by Leuckart to be the adult condition of the still better known Pentastoma denticulatum. It resides in the nasal sinuses. As already mentioned in a former part of this work, these parasites present four marked stages of growth, namely (1), the embryo, (2) the pupa, (3) the active larva (P. denticulatum), and (4) the sexually-mature worm. As the eggs and their embryonic contents are lodged in the nasal mucus of the dog, and are commonly distributed by the act of sneezing on the part of the animal, the sources of infection are not far to seek. Clearly the larvæ usually get introduced to the bodies of mankind and herbivorous animals by the ingestion of unclean vegetable matter. The embryos set free in the stomach bore their way to the liver and other viscera, in which organs encystation and moulting subsequently take place. The fondling of dogs infested by pentastomes may prove dangerous by a more direct transference of the eggs to the hands and mouth. As regards the dog, the adult parasite has been known to prove fatal. A very striking instance of this kind was recorded by Prof. Dick, where the worms wandered into the trachea producing asphyxia.
The ectozoa of the dog, though not numerous as species, are of importance in relation to mange. The follicle-mites form a family by themselves (Demodicidæ), and, as already observed, those infesting the dog and cat are, alike, mere varieties of the human species (Demodex folliculorum, var. caninus and var. cati). Whilst the human parasite restricts itself to the face, the canine variety (fig. 52) will occupy any part of the dog’s body. The follicle-mite of the cat, however, usually confines itself to the ear. According to Mégnin, to whose beautiful monograph we owe so much, two or three dozen of these parasites may be found occupying a single follicle of the dog. Acne-like pustules are thus formed, and when they are very numerous death may result from the excessive irritation, which is usually accompanied with depilation. An interesting example of this kind recently occurred at the Royal Veterinary College. In regard to the ordinary mange-mite (Sarcoptes canis, Gerlach) M. Mégnin points out that it is in all respects identical with the human itch-insect. In the wolf and fox, however, the same species forms well-marked varieties (S. scabiei, var. lupi and var. vulpis). As regards true insect parasites and tormentors of the dog, I can only allude to a few of them. In tropical America dogs are said to be attacked by the larvæ of a species of gadfly (Œstrus canis), whilst in Africa they are often fatally bitten by the tsetse (Glossina morsitans). In addition to the flies (Diptera), several kinds of fleas (Aphaniptera) frequently prove troublesome (Pulex canis, P. martis, and P. penetrans), and the same may be said of certain lice (Hemiptera). The common louse of the dog (Trichodectes latus) proves especially noxious to young puppies. Of the two other species, namely, Hæmatopinus piliferus and H. canis, the former is tolerably common, whilst the latter is comparatively rare. This species is also found on the ferret. A new form of mite (Chorioptes ecaudatus), infesting the ears of the ferret, has recently been described by M. Mégnin.
I have already referred to several of the parasites of the cat-tribe (Felidæ), but some others require notice. Only two flukes (Amphistoma truncatum and Hemistoma cordatum) have been described as infesting the cat. Of the tapeworms, Tænia crassicollis is the best known. This is derived from Cysticercus fasciolaris of the mouse and rat. It is not uncommon to find this scolex in the sexually-immature tænioid state in the liver, measuring six or seven inches in length. An exceedingly interesting communication by Dr Romano, of Gemona (Frioul), demonstrates the possibility of severe feline epizoöty as due to this entozoon. As I gather from an account given in the journal quoted below, “during the summer of 1876, Dr Romano was informed by his confrère Dr Leoncini, a physician practising at Osoppo, that for about a fortnight most of the cats in a certain hamlet of the town had died without appreciable cause after presenting the following symptoms:--Gradual wasting, with complete loss of appetite, retracted abdomen, slight diarrhœa at first, then constipation, abundant saliva, contraction of the elevating muscles of the upper lip in some subjects, great prostration of strength, loss of the visual faculty. Some of the feline patients no longer heard or appeared no longer to hear their master’s voice; some vomited and seemed to experience relief, for the appetite improved, but they soon died like the others. Nervous phenomena, epileptiform convulsions, and more frequently colic, also showed themselves. Having visited the locality (of the outbreak), Dr Romano could not at first procure any corpses for the post-mortem examination, for the children had thrown them into the Tagliamento, which flows at the foot of the fortress of Osoppo. It was only after the lapse of some days that he was able to open one of the animals which had just succumbed. The principal evils were remarked in the stomach, the walls of which were retracted and formed the seat of a catarrhal inflammation, from the products of which a long, white, flat worm was removed with care for examination. All the other organs were in good condition. The examination of the helminth in the stomach, made with the help of Dr Leoncini and Fachini, showed that the flat worm (white, and with the body divided into rings, 12 centimètres long, and 5 or 6 millimètres broad) had all the characters of the tænias, and this was confirmed by a microscopic examination of the head. A few days later Dr Romano made an autopsy of two other cats. In one of the corpses he noted the alterations described above, and found a tænia smaller than the first; in the other the same lesions without any helminth. This negative circumstance very naturally disconcerted Dr Romano, but several people of the place came to assure him that they had seen their cats, during the course of the malady, after violent and repeated efforts at vomiting, throw up a sort of white cord, which they recognised as corresponding with the tænia he showed them. Thus confirmed and reassured in his diagnosis, Dr Romano sought to identify the species.” In this connection it is specially interesting to note that “during the whole summer the inhabitants of Osoppo had been over-run by bands of rats proceeding from the fortress. They were combated by means of cats, and it was the best hunters among the felines that succumbed. Here was, therefore, a striking relation of cause and effect which could not be gainsayed.” Dr Romano communicated his observations to the National and Royal Veterinary Society, but by an error in the report the species appears to have been described as Tænia tenuicollis instead of T. crassicollis. In this connection I have only further to add that the wild cat is infested by a tapeworm scarcely an inch in length (Tænia lineata). A species of Bothriocephalus (B. decipiens) likewise infests the domestic cat, in common with most of the wild felines, such as the tiger, puma, ounce, and jaguar. Dr Bancroft brought me a specimen from an Australian cat. The nematodes of the cats are very abundant. Dr Bellingham found a trichosome (T. felis cati) in the urinary bladder of the wild cat. This is probably identical with T. plica. A tolerably common nematode is Dochmius tubæformis, which occurs not only in the cat but also in the leopard, puma, jaguar, ounce, panther, and also in Felis tigrina and F. mellivora. In the last-named and in other Brazilian felines an echinorhynchus (E. campanulatus) was found by Natterer. A strongyle (Sclerostoma dispar) infests the lungs of the puma. A species of spiroptera (S. subæqualis, Molin) infests the œsophagus and stomach of the lion and tiger. Redi also noticed a species of Filaria beneath the skin of the lion. Physaloptera terdentata (Molin) and P. digitata (Schneider) infest the stomach of the puma. I can only allude also to Tænia laticollis of the lynx, Pentastoma recurvatum, occupying the frontal sinuses and air-passages of the ounce, and Ligula reptans the subcutaneous tissues of the leopard. Lastly, there is the Olulanus tricuspis of the domestic cat. I have examined the lungs of three cats containing this parasite, which was first described as an entirely new species by Leuckart. The adult worms, only 1/25″ in length, occupy the walls of the stomach. Thence they are apt to migrate or stray into the lungs and liver, where they encyst themselves. When myriads of them are thus encysted a kind of nematode tuberculosis is set up. This disease I have elsewhere called olulaniasis. Ordinarily, however, the encysted condition of olulanus is to be found in the muscles of mice, which are thus said to be olulanised. Clearly, as Leuckart’s experiments substantially prove, the domestic cat acquires the adult worm by catching and devouring olulanised rodents. Every now and then the disorder thus created produces a virulent and fatal feline epizoöty.
BIBLIOGRAPHY (No. 45).--(Anonymous), “Curious Note on two Tænia from the Dog (asserting that neither strong whisky nor boiling water would kill them),” ‘Med. Commentaries,’ vol. xvi, p. 370, 1791.--Araujo, A. J. P. S., “A Filaria immitis e F. sanguinolenta no Brazil,” ‘Gazeta Medica da Bahia,’ Julho de 1878.--Baillet, C., “On Dochmius, and on a Worm found in the Heart and Vessels of a Dog,” from ‘Journ. Vet. du Midi,’ in the ‘Veterinarian,’ p. 549, 1862.--Baird, W., “Note on the Spiroptera sanguinolenta found in the Heart of Dogs in China,” ‘Proc. Linn. Soc.,’ vol. ix, Zool. Div., p. 296, 1867.--Balbiani (l. c., Bibl. No. 28).--Beneden (see Van Beneden, below).--Bickford (l. c., Bibl. No. 28).--Chapman, “On Ascaris mystax (leptoptera) in the Tiger and American Wild Cat,” ‘Proc. Acad. Philad.,’ 1875, pp. 14 and 17.--Cherry, E. F., “Worms in the Stomach of a Dog,” in the ‘Farrier and Naturalist,’ 1829, vol. ii, p. 303.--Clamorgan, J. de, “Serpents dans les reins,” in his ‘La Chasse du Loup,’ 1570; see also Bibl. No. 28.--Cobbold, “On the Prevalence of Entozoa in the Dog, in relation to Public Health,” ‘Journ. Linn. Soc.,’ vol. ix (Zool. Sect., No. 37, p. 281), 1867; also in ‘Lancet,’ April 27, 1867, p. 521; and in supp. to ‘Entozoa,’ 1869.--Idem, “Observ. on Entozoa, with experiments in regard to Tænia serrata and T. cucumerina,” ‘Linn. Trans.,’ 1858.--Idem, “On some new Forms of Entozoa,” ‘Linn. Trans.,’ 1859.--Idem, “Further Observ. on Entozoa, with Experiments,” ‘Linn. Trans.,’ 1861.--Idem, “On Filaria immitis,” ‘Proc. Zool. Soc. of Lond.,’ Nov. 18, 1873, p. 736.--Idem, “Observ. on Hæmatozoa,” in the ‘Veterinarian,’ Oct., 1873.--Idem, “Parasites of the Dog,” in ‘Manual,’ 1874, l. c., chap. ix, p. 86.--Idem, “Description of a new generic type of Entozoon (Acanthocheilonema) from the Aard Wolf (Proteles),” ‘Proc. Zool. Soc. of Lond.,’ Jan. 13, 1870.--Idem, “On Diatoma compactum,” in ‘Linn. Trans.,’ vol. xxii, p. 363, ‘Proc. Zool. Soc.,’ March, 1861.--Idem, various letters on “Canine Epidemics in relation to Lumbricoid Worms in Dogs,” in the ‘Field,’ Dec., 1872.--Idem, “Remarks on the Life-epochs (biotomes) of T. cœnurus and T. echinococcus,” in a paper on ‘Animal Individuality,’ ‘Journ. Linn. Soc.,’ Zool. Div., vol. viii, p. 163.--Idem, “Worms in the Heart (Mr. M’Innes’ specimen from Charleston),” the ‘Veterinarian,’ Feb., 1875.--Idem, “Note of Lewis’ Discoveries,” in ‘Nature,’ March 11, 1875, vol. ii, p. 363.--Idem, “Remarks on Eustrongylus gigas” in the ‘Veterinarian,’ April, 1879.--Coles, E. C., “Worms in the Heart and Œsophagus of a Dog,” ‘Path. Soc. Rep.,’ March, 1878.--Dare, J. J., “Death of Dogs from Worms in the Heart,” the ‘Field,’ Feb. 24, 1872.--Davaine, ‘Traité,’ l. c., 2nd edit., p. 290 (for refs. to lit. of Strongylus gigas).--Delafond (with Grube), “Note on a Verminiferous kind of Blood of a Dog, caused by Hæmatozoa of the genus Filaria,” from ‘Ann. de Chimie et de Physique,’ in ‘Ann. of Nat. Hist.,’ vol. xi, 1843, and ‘Comp. Rend.,’ in ‘Lond. Phys. Journ.,’ p. 28, 1843; also from ‘Gaz. Med.,’ in ‘Med.-Chir. Rev.,’ vol. xxxv, p. 393, 1843-44; see also ‘Edin. New. Phil. Journ.,’ vol. lii, p. 233, 1852, and ‘Veterinarian,’ vol. xviii, p. 216, 1845.--Dick, “Worms the cause of Sudden Death in a Dog,” the ‘Veterinarian,’ vol. xii, p. 42, 1840 (Pentastomes).--Diesing, ‘Syst. Helm.,’ vol. ii, p. 327 (Eustrongylus).--Ercolani, G. B., “Osservazione elmintologiche sulla dimorfobiosi nei Nematodi, sulla F. immitis e sopra una nuova specie di Distoma dei cani,” ‘Mem. Accad. Bologn.,’ v, 1874-5.--Frank (see Bibl. No. 28).--Gay, J., Specimen of Olulanus in Hunterian Museum, and marked in the ‘Catalogue’ “No. 1814A, Lung of Cat, pneumonic, from the presence of parasites.”--Gay, “Nematodes of Panther,” in ‘Hering’s Repert.,’ 1873, from ‘Il. Med. Vet.’--Herbst, “On Trichinæ in the Badger,” from ‘Ann. des Sci. Nat.,’ in ‘Assoc. Med. Journ.,’ 1853, vol. i, p. 491.--Hoysted (and Sir J. Fayrer), “On Filaria sanguinis (really F. immitis),” ‘Lancet,’ March 1, 1879, p. 317.--Jamieson (see Manson).--Jardine (see Manson).--Klein, J. T., “Worms found in the Kidneys of Wolves,” ‘Phil. Trans.,’ vol. xxxvi, 1729.--Krabbe, “Husdyrenes Indvoldsorme,” ‘Tidsskrift for Veterinairer,’ 1872.--Leblanc, “Subcutaneous Tumour in the Dog, due to the presence of Strongylus gigas,” from ‘Recueil de Méd. Vét.,’ in ‘Edin. Vet. Rev.,’ Dec., 1863; see also Bibl. No. 28.--Idem (see Mégnin).--Legros, “Hæmatozoa of Dogs,” in ‘Rec. de Méd. Vét.,’ i, p. 947.--Leisering, “On Hæm. subulatum,” in ‘Virch. Archiv,’ 1865.--Leuckart (see Bibl. Nos. 28, 29).--Idem, (for development of T. serrata, &c.), ‘Die Blasenbandwürmer und ihre Entwicklung,’ Giessen, 1856.--Idem, ‘Bau und Entwicklungsgeschichte der Pentastomen (especially P. tænioides and P. dent.),’ Leipzig, 1860.--Idem, ‘In relation to the genus Dochmius,’ see his standard work, l. c., s. 433, and also ‘Arch. f. Heilkunde,’ Bd. ii, s. 212 (see also Parona).--Lewis, T. R., “On Nematoid Hæmatozoa of the Dog,” ‘Quart. Journ. Micr. Soc.,’ 1875, vol. xv.--Idem, “On Filaria sanguinolenta, Echinorhynchus, &c., from the Dog,” in his oft-quoted ‘Memoir,’ Calcutta, 1874.--Linstow, O. von, “Ueber die Muskulatur, Haut und Seitenfelder von Filaroides mustelarum, v. Ben.,” ‘Arch. f. Naturg.,’ xl, s. 135 (with figs.).--Idem, “Einige neue Nematoden,” &c., ‘Arch. f. Naturg.,’ p. 293, Bd. xxxix.--Manson, P., “On F. sanguinolenta and F. immitis,” in his ‘Report on Hæmatozoa,’ in the ‘Customs Gaz.,’ No. xxxiii (with numerous figs.), Jan.-March, Shanghai, 1877. (N.B.--The same journal, Rep. No. 12, Gaz. No. xxx, contains remarks on worms in the heart of dogs by Dr A. Jamieson. The subject is also discussed by Dr Jardine.) See also ‘Med. Times and Gaz.,’ Oct. 20, 1877, p. 480.--Mather, T., “Filariæ found in the Intestines of a Dog,” ‘Veterinarian,’ vol. xvi, p. 434, 1843.--McConnell, “On D. conjunctum,” ‘Lancet,’ March 30, 1878, p. 476.--Mégnin, P. “On Myobia,” ‘Abhandl. ueber eine neue Gruppe von Acariden (u. s. w.),’ in ‘Revue f. Thierheilkunde,’ Oct., 1878, p. 149.--Idem, “Sur un parasite des oreilles chez le furet,” ‘Rec. de Méd. Vét.,’ Oct., 1878.--Idem (avec C. Leblanc), “Note sur le Cysticercus cellulosæ developpé chez le chien,” ‘Bullet. de la Soc. cent. vét. de Paris,’ 1873.--Idem, “Sur le Strongylus gigas,” Bullet. de la Société Entom. de France, No. 3, 1879.--Melnikow, N., “On Tænia cucumerina,” in ‘Arch. f. Naturg.,’ 1869, p. 62.--Miller, E., ‘Six Cases of Strongyle in the Kidney of Putorius vison’ (quoted by Davaine from Museum of Boston, U.S.).--M’Innes (see Cobbold).--Molin, ‘Nuovi myzelmintha,’ s. 34, 1859.--Idem, ‘Una monog. del gen. Physaloptera (P. tordentata),’ 1860, s. 17.--Idem, ‘Una monog. del gen. Spiroptera (S. subæqualis),’ 1860, s. 13.--Nettleship, E., “Notes on the Rearing of Tænia echinococcus in the Dog from Hydatids, with some observations on the anatomy of the adult worm,” ‘Proc. Roy. Soc.,’ 1866, No. 86, p. 224, with figs.--Noseda, B., “Six Strongyles in the Kidney of the Agouara-gouazura or Puma,” in Don F. de Azara’s ‘Quadrupèdes du Paraguay,’ Paris, 1801 (see also Azara, Bibl. No. 28).--Osborne, T. C., “Worms found in the Heart and Blood-vessels of a Dog (with symptoms of hydrophobia),” ‘Western Med. Journ.,’ rep. in ‘Bost. Med. and Surg. Journ.,’ vol. xxxvii, p. 448, 1847-48.--Osler, W., “Verminous Bronchitis in Dogs (from Strongyles),” ‘Veterinarian,’ June, 1877, p. 387.--Owen, “On the Anatomy of Linguatala tænioides,” ‘Trans. Zool. Soc.,’ vol. i, 1835, and in ‘Lond. Med. Gaz.,’ 1835.--Idem, “Anatomical description of two species of Entozoa, from the Stomach of a Tiger, one of which forms a new genus, Gnathostoma,” ‘Proc. Zool. Soc.,’ part iv, 1836.--Parona (and Grassi), “On a new Species of Dochmius (D. balsami),” ‘Reale Instituto Lombardo di Scienze e Lettere, Rendiconti,’ vol. x, fasc. vi, 1877.--Raynold, T. M., “Tapeworm in the Pointer and Spaniel,” ‘Veterinarian,’ vol. xiv, p. 694, 1841.--Romano, “Epizoöty amongst Cats from Tænia crassicollis,” ‘Giornale di med. vet. practica,’ Août, 1877, and in ‘Journ. de Méd. Vét.,’ Avril, 1878.--Schuppert, M., “Mechanical Obstruction of the Heart (of a Dog) by Entozoa, causing Death,” ‘New Orleans Med. News and Hosp. Gaz.,’ Jan., 1858, also ‘Bost. Med. and Surg. Journ.,’ vol. lvii, 1857-58, and in ‘Med.-Chir. Rev.,’ 1858.--Stirling, “On the Changes produced in the Lungs by the Embryos of Olulanus tricuspis,” ‘Quart. Journ. Micr. Sci.,’ 1877, p. 145.--Van Beneden, “On the Transmigration of the Entozoa” (in answer to MM. Pouchet and Verrier), from the French, by Busk, in ‘Quart. Journ. Micr. Sci.,’ 1862.--Idem, “Researches on the Intestinal Worms,” from Van der Hoeven’s abstr. in the ‘Nederlandsch Tijdschrift voor Geneeskunde,’ in ‘Ann. Nat. Hist.,’ vol. iii, 3rd ser., 1859.--Idem, “New Obs. on the Development of the Intestinal Worms,” from ‘Compt. Rend.,’ in ‘Ann. Nat. Hist.,’ vol. xiii, 2nd ser., 1854.--Idem, “On Filaroides mustelarum,” ‘Mém. sur les vers intest.,’ 1858, p. 267.--Welch, “On Filaria immitis,” ‘Lancet,’ March 8, 1873; also in ‘Month. Micr. Journ.,’ Oct., 1873, p. 157 (with three plates).--Wilson, W., “A Parasitic Worm infesting the Air Sinuses of the Weasel,” ‘Midland Naturalist,’ May, 1878.--Wright, “On Worms found in the Pulmonary Artery of a Dog,” ‘Lancet,’ 1845, and in ‘Veterinarian,’ vol. xviii, p. 52, 1845.--Youatt, “On Tumours (containing Entozoa) in the Stomach of a young Tiger,” ‘Veterinarian,’ vol. x, p. 619, 1837; see also Owen on ‘Gnathostoma.’--Idem, “Worms (Ascaris marginata) in the Nose of a Dog,” ‘Veterinarian,’ vol. v, p. 337, 1832.
V. (PINNIPEDIA)
Following the order of classification adopted in my description of the Mammalia in the ‘Museum of Natural History,’ I proceed to speak of the internal parasites of the seals (Phocidæ) and walruses (Trichecidæ). From their piscivorous habits one would naturally expect the seals to be largely infested with entozoa, and yet, though sufficiently victimised, they are not liable to entertain so great a variety of helminths as the fishes themselves on which they feed.
The flukes observed in Phoca vitulina are Distoma acanthoides and Amphistoma truncatum, the latter occurring also in P. grœnlandica. In another seal (P. barbata) we have D. tenuicolle. The nematodes are more numerous. The best-known is the maw-worm (Ascaris osculata), which seems to be always present in full-grown seals of every kind. In the years 1862-64 I conducted a series of experiments with the eggs of this worm. I reared embryos both in salt and fresh water, but the administration of the young worms to various animals led to no result. However, I succeeded in watching the growth of the embryos until they had acquired well-marked digestive organs and a length of 1/25″, their size when emerging from the egg-shell in the water having been about 1/150″ only. The large strongyle (Eustrongylus gigas) has been found in various organs of the common seal. Of more interest are the Filariæ found in the heart of seals, which in many respects resemble those obtained from the same situation in dogs. Professors Joly, Leidy, and myself, have each described a species, but apparently our descriptions all refer to one and the same parasite. It has also been seen by Camill Heller. The close correspondency in size and other characters of Leidy’s Filaria spirocauda and my Filaria hebetata leaves little doubt as to their identity. As the worms were both originally noticed by Leidy and Joly in 1858, I cannot pronounce upon the question of priority of discovery. By Joly the worm was called F. cordis phocæ. In Leidy’s and in my own specimens the males were four inches long, and the females six inches; they extended up to 8″ in some of the American examples. The worms found by Prof. Joly were all females. Professor Millen Coughtrey, who furnished me with the seal’s heart, stated that it was obtained from a male hoodcap (Stemmatopus cristatus), a rare visitant of our British coasts. This seal was captured on the Cheshire side of the Mersey river. Leidy and Joly obtained their specimens from Phoca vitulina. In the common seal have also been found Ligula crispa, Schistocephalus dimorphus, and Echinorhynchus strumosus. In other seals a not uncommon tapeworm of the Bothriocephalous type is that called Dibothrium hians by Diesing. To Prof. Krabbe I am indebted for a specimen of Bothriocephalus fasciatus taken from Phoca hispida. There is a nematode of frequent occurrence in P. hispida and P. grœnlandica. This is the Ophiostoma dispar of Rudolphi. In addition to the above I can only add that P. barbata is infested by Liorhynchus gracilescens, occupying the stomach, and by a tapeworm, Tetrabothrium anthocephalum, which is found in the lower part of the large intestine.
BIBLIOGRAPHY (No. 46).--Cobbold, “Description of F. hebetata,” in ‘Notes on Entozoa,’ part i, sp. 3, ‘Proc. Zool. Soc.,’ Nov. 18th, 1873, p. 741.--Idem, “On Ascaris osculata,” in ‘Report of Experiments respecting the development and migrations of the Entozoa;’ ‘Brit. Assoc. Trans.,’ 1864, p. 114.--Heller, C., in ‘Schrift der zool.-botan. Gesellsch.,’ Wien, 1858, s. 83.--Joly, “On a new Species of Hæmatozoon of the genus Filaria, observed in the heart of a seal;” from ‘Compt. Rend. Acad. Sci.,’ 1856, p. 403, in ‘Ann. Nat. Hist.,’ vol. i, 3rd ser., 1858; also abstr. in the ‘Year Book,’ 1859.--Leidy, J., (E. spirocauda) in ‘Proc. Philad. Acad.,’ 1858, p. 112.
VI. (RODENTIA)
Though very numerous, the parasites of this order are chiefly interesting as embracing those of the hares and rabbits, moles, mice, rats, squirrels, and beavers. Some slight notice, however, will be given of the entozoa of each of the eleven families into which the order may be divided.
The squirrels (Sciuridæ) are liable to be infested by the common liver fluke (F. hepatica), and also, it is said, by a cysticercus (C. tenuicollis). I have never encountered this bladder worm, but in 1864 I described some polycephalous hydatids (Cœnuri) which I obtained from the viscera of an American squirrel. I think the host was of the same species (Sciurus vulpinus) as that from which Mr Chapman has since obtained an example of Echinorhynchus (E. moniliformis). This worm also infests the hamster. A very small female round worm, probably a strongyle, was described by Rudolphi as Ascaris acutissima. It infests the cæcum of the common squirrel, in which host a species of tapeworm is tolerably frequent (Tænia dendritica). The common European marmot is infested by T. pectinata, so abundant in hares and rabbits. I have also noticed it as occurring in the Canadian porcupine (Hystrix dorsata). The dormice (Myoxidæ) are not much troubled with parasites, at least I have not encountered any in our common Myoxus avellanarius. In M. glis, however, a tapeworm, and at least one species of strongyle (S. gracilis), have been observed. Dujardin described very fully another strongyle (S. lævis) from M. nitela, from the long-tailed field-mouse (Mus sylvatica), and from Arvicola subterraneus. The other species are Trichosoma myoxi nitelæ, and Ophiostoma cristatum from Myoxus dryas, and M. muscardinus. The jerboas (Dipodidæ), in common with the hamster and several species of true mice, are apt to be infested by Ascaris tetraptera; and a small nematoid, apparently immature, was noticed by Otto in the intestines and in the abdominal walls and cavity of Dipus tetradactylus. Mice, properly so called, are largely infested, as is also the hamster (Cricetus vulgaris), which I include in the Muridæ. In addition to the parasites already mentioned, the hamster is infested by Tænia straminea. Along with examples of this tapeworm I have received from Dr Murie some acephalocysts found in a hamster which died at the Zoological Gardens.
Flukes exist in the long-tailed field-mouse (Distoma vitta and D. recurvum), but I have not seen any in our common mice and rats. However, Dujardin describes a distome (D. spiculator) in the brown rat (Mus decumanus). One of the tapeworms observed in the mouse (M. musculus) is Tænia pusilla, also found in the rat (M. rattus) and long-tailed field-mouse. The house-mouse likewise harbors T. microstoma and T. leptocephala; and an immature cestode has also been seen in the abdomen, probably a species of Ligula. Various species of rat also harbor T. diminuta. In regard to the round worms one of the most common species is Ascaris oxyura. This not only occurs in rats and mice, but also in voles, water-rats, and many other rodents. The rodents’ whipworm (Trichocephalus nodosus) is yet more common in the lemmings, rats, voles, and mice; another species (T. unguiculatus), taking its place in hares and rabbits, and yet another (T. affinis) in the porcupine. Another nematoid, very common in mice, is Spiroptera obtusa, occupying the stomach. I have seen a mouse with its abdomen so distended by their presence that the animal could scarcely run along the pathway where it was killed by being trod upon. According to Marchi, the young of this entozoon dwell in the fat surrounding the alimentary canal of the larva of an insect (Tenebrio molitor). When noticing the parasites of the cat I referred to Leuckart’s interesting discovery of the relations subsisting between the adult Olulanus tricuspis, found in the stomach walls of that feline, and the immature encysted worms, found not only as wanderers in the cat itself but also in the muscles of mice. The olulanised mouse is thus an intermediate host. Rats and mice also play the part of intermediary bearers in the case of two other species of entozoa, namely, Trichina spiralis and Tænia crassicollis, the tænioid scolex or larval condition of the cat’s tapeworm being familiarly known as Cysticercus fasciolaris. This sexually-immature tapeworm infests many other rodents, especially the voles (Arvicolidæ). In regard to Trichinæ it must not be forgotten that their presence in rats is not uncommon in some parts of Europe; and this circumstance may explain the recurrence of trichinosis (first in hogs and then in man) in certain outlying districts. Only in this way can the Cumberland outbreak in this country be accounted for. Here I cannot dwell upon the subject, but in this connection I may observe that Bakody has in a very convincing manner described a new variety or species of Trichina, found by him infesting the walls of the stomach and intestine of rats. In the first instance he detected the worm in association with the ordinary T. spiralis, but afterwards separately. He also obtained it in fowls. The species should be called Trichina Bakodyii. Possibly the nematodes observed by Colin in 1863 also refer to this worm. They occupied tubercles in the liver of a rat. In regard to the beavers (Castoridæ) it appears that they harbor many species of round worms, and also several flukes, but they do not appear to have been very much studied. In Morgan’s work on the American beaver there is a notice in which it is stated that Dr Ely found a very fine filamentous worm 40‴ in length. This does not seem to correspond with Ascaris castoris (Rud.). He also speaks of large numbers of a slender white worm, 3″ to 5″ in length, found in the peritoneal cavity, and referable to the genus Filaria. This cannot be confounded with Trichocephalus castori (Rud.). Moreover, he describes a strongyle (Sclerostoma) as infesting the colon, and especially the cæcum. These all appear to be new to science. The Fasciola hepatica is occasionally found in the liver, but the most common helminth of beavers is Amphistoma subtriquetrum. Specimens of this worm may be seen in the British and Hunterian Museums. As regards the porcupines (Hystricidæ) I have already mentioned the occurrence of a tapeworm in the common species. The larval Pentastoma denticulatum has been found by Otto attached to the surface of the lungs, and Redi, about two centuries back, noticed small nematodes lodged in tubercles of the œsophagus. The late C. M. Diesing obtained Trichocephalus affinis from the intestines. So far as I am aware, little or nothing has been said respecting the helminths of the Octodontidæ, Chinchillidæ, and Cavidæ. Like other European investigators I have dissected guinea pigs (Cavia aperœa) without finding any parasites; but in Brazil a small species of ascaris (A. uncinata) was found by Natterer in this animal and also in the paca (Cœlogenys paca). The agoutis (Dasyprocta) harbor Trichocephalus gracilis.
The entozoa of the duplicidentate rodents (Leporidæ) acquire importance from the fact of their abundance and from the intimate relation which some of them bear to parasites infesting the dog and other animals. Thus, the two commonest kinds of fluke infesting cattle (Fasc. hepatica and Dist. lanceolatum) also attack hares and rabbits; the former parasite often producing the rot disease, which is almost as fatal to the rodents as it is to the ruminants. Mutual infection occasionally results from this circumstance by the distribution of germs. All experiment-conducting helminthologists have reared Tænia serrata from the Cysticercus pisiformis; nevertheless, several English Manuals of Zoology persist in propagating the old error of Von Siebold, who supposed he had reared this tapeworm by the administration of Cœnuri. So far as I am aware, no feeding experiments have been conducted with the Cœnuri of rabbits (C. cuniculi). These bladderworms infest the soft parts of the body, often producing tumours having a very unsightly appearance. For details I must refer to the papers quoted below. The Norfolk warreners call the infested hosts “bladdery rabbits.” Though apparently most abundant in the eastern counties of England, these diseased rabbits are by no means confined to that quarter. Through Mr Alston’s help I have received specimens of Cœnurus cuniculi from Ayrshire, Scotland. Probably this form of Cœnurus occurs wherever rabbits live. In Italy a case is recorded by Perroncito from the abdominal cavity of a rabbit (coniglio). Every experimenter is more or less familiar with the cestode larvæ (C. pisiformis) found wandering in the abdominal cavity. These were regarded as flukes by Kuhn (Monostoma leporis). I need hardly remark that the developmental and structural changes undergone by these Cysticerci during their residence within the rabbit have been exhaustively followed out and treated of by Leuckart. Without dwelling on this subject, I must in justice add that in this relation the special labors of Küchenmeister, Van Beneden, Haubner, Wagener, Röll, Eschricht, and Möller played no inconspicuous part. My own efforts in 1857, and subsequently, were not unattended with success. It therefore seems to me, without prejudice to the recent experiences of De Sylvestre and others, that further experiments in this immediate connection are unnecessary. As regards the nematodes of leporine rodents, probably the most important is Strongylus commutatus. This parasite, like its husk-producing congeners, infesting calves and lambs, occasionally sweeps off great numbers of hares. Such an epizoöty occurred in Thuringia in 1864. The most frequent intestinal parasite of rodents is probably Oxyuris ambigua, but Strong. retortæformis is tolerably abundant in the hare, and Trichocephalus unguiculatus is liable to occur in all leporines. I know nothing of the so-called Strong. strigosus of rabbits, but Bellingham found it in Ireland. Olfers and Natterer obtained a small ascaris (A. veligera) from Lepus braziliensis; but I cannot help thinking that the large measle (Cysticercus macrocystis) described by Diesing as three inches in length, and obtained from the same rodent, must either have been Cœnurus cuniculi or else another form of polycephalous hydatid.
In reference to the ectozoa of rodents it may be said that they are very numerous. Acari infest rats and mice, and especially leporines. Thus, in the mouse are found Sarcoptes notoedre, Bourguignon, var. muris, Mégnin, Sarc. musculinus, Koch, and Myobia musculi, Claparède. It is not very generally known that wild rabbits are apt to be attacked by the common autumnal spider (Leptus autumnalis), whence, as once happened with myself, they may be transferred to the human body. The ears of tame rabbits are sometimes covered with acari, which are easily destroyed by the cautious application of a mixture of carbolic acid and olive oil (one of acid to six of the oil). Rodents also harbor fleas. At a meeting of the Entomological Society in 1875 Mr Vernall showed living specimens from the ears of a rabbit, and Messrs Cole and W. A. Lewis stated that they had obtained fleas from the hedgehog and European marmot respectively.
BIBLIOGRAPHY (No. 47).--Beneden (see Van Beneden below).--Capelle, J., Extr. from a letter, in which the author states that he had “found worms of the tænia kind in the liver of sixteen out of eighteen rats,” ‘Med. Commentaries,’ vol. xix, p. 139, 1794; see also ‘Trans. Coll. Phys. of Philad.,’ vol. i, part ii, p. 60, 1793.--Chapman, H. C., “Echinorhynchus in Squirrel,” ‘Proc. Acad. Philad.,’ 1874, p. 76.--Cobbold, “Note on Cœnurus (from a squirrel),” ‘Proc. Linn. Soc.,’ May 5, 1864.--Idem, “On the occurrence of Tænia pectinata in the Porcupine (Hystrix dorsata),” in a letter to Dr. Lawson in the ‘Canadian Naturalist and Geologist,’ 1862.--Idem, ‘On T. serrata,’ &c. (see Bibl. No. 45).--Colin, “On the presence of a Nematode Worm in certain Tubercles of the Liver of a Rat,” from ‘Rec. de Méd. Vét.,’ in ‘Edin. Vet. Rev.,’ Oct., 1863.--Leuckart, ‘Die Blasenbandwürmer (u. s. w.),’ 1858 (contains numerous details and figs. in ref. to Cysticercus pisiformis and T. serrata, &c.).--Marchi, P., ‘Mem. della R. Accad. d. Sci. di Torino,’ xxv.--Peacock, “Remarks on the Liver of a Mouse with Cysts containing Cysticerci,” ‘Lancet’ and ‘Trans. Path. Soc.,’ 1855.--Perroncito, E., “Sopra un caso di Cœnurus (in the abdominal cavity of a rabbit),” ‘Giornale Med. Veter.,’ 1876.--Siebold (see Von Siebold, below).--Sylvestri, De, “Experiments with C. pisiformis,” ‘Il. Med. Veterinario,’ 1871.--Van Beneden (see Bibl. No. 45).--Idem, “On Sciurus glacialis and its Parasites,” from ‘Bull. de l’Acad. de Belgique,’ in ‘Ann. Nat. Hist.,’ vol. xiii, 1854.--Verrall, in ‘Proc. Ent. Soc. Lond.,’ Feb. 15, 1875, p. 3.--Von Siebold, ‘Ueber die Band-und Blasenwürmer,’ Leipsig, 1854, and Huxley’s edit. for Syd. Soc., 1857.--Idem, “Experiments on the Transformation of the Cystoid Worms into Tænias,” from ‘Ann. des Sci. Nat.,’ in ‘Ann. Nat. Hist.,’ vol. x, 1852.--Idem, “Helminthology,” trans. by Busk and pub. in ‘Ray Soc. Rep. on Zool.,’ 1843-44, p. 446, London, 1847.--Idem, “On the Transformation of Cysticercus pisiformis into Tænia serrata,” from ‘Zeitsch. f. w. Zool.,’ in ‘Quart. Journ. Micr. Sci.,’ 1854.
VII. (EDENTATA)
The entozoa of the edentulate mammals are not very numerous. So far as I am aware only one species has been described from the scaly ant-eaters (Manidæ). This is the small and probably immature ascaris noticed by Whitefield in the walls of the stomach of the badgareit or short-tailed pangolin (Manis pentadactyla). Amongst the true ant-eaters (Myrmecophagidæ) a single round worm has also been observed, but not adequately described. I allude to Marcgrav’s “find” in the little ant-eater (Myrmecophaga didactyla). I observe that Rudolphi distinctly refers to this edentate as the tamandua. Diesing does the same. The ant-eaters are much infested by a thorn-headed worm (Echinorhynchus echinodiscus). On the 1st November, 1875, I received from Prof. Flower a jar labelled as follows: “Entozoon found attached to intestine of tamandua ant-eater.” The parasite was procured from the society’s gardens on August 12th, 1871. Natterer originally obtained this worm from Myrmecophaga jubata and M. bivittata. Croplin described it from a M. didactyla from Surinam (‘Wiegmann’s Archiv,’ 1849). I presume that M. tamandua answers to the M. bivittata of Geoffroy, as well as to the tridactyle and tetradactyle species of Linnæus. The parasite in question was a female, measuring exactly 10 inches long, and had its proboscis firmly anchored within the gut. The armadillos (Dasypidæ) entertain a variety of nematodes. In 1858 I obtained several examples of Ascaris retusa from the rectum of a poyou or weasel-headed armadillo (Dasypus sexcinctus). The worm was first procured by Natterer from the black armadillo (D. peba), which host also harbors Pentastoma subcylindricum. According to the “finds” of Natterer and the subsequent descriptions by Diesing, the two most common helminths of the Brazilian armadillos are Aspidocephalus scoleciformis and Trichocephalus subspiralis. As regards the sloths (Bradypidæ) it would seem that they are particularly liable to entertain round worms. The Ai (Bradypus tridactylus) is infested by Strongylus leptocephalus, Spiroptera gracilis, Sp. anterohelicina, and Sp. brachystoma; whilst the unau (Cholœpus didactylus) harbors the last-named species and also Sp. spiralis. All these worms have been described by Molin, and, with the exception of the two first named, were new to science when he wrote his well-known monograph on the genus. They were collected by Natterer. All the species infest either the stomach or intestines, with the exception of Sp. spiralis. This singular worm, like the closely allied Sp. helicina, infesting the feet of birds, has the habit of coiling itself amongst the tendons of the digits of the hind limbs more especially.
BIBLIOGRAPHY (No. 48).--Cobbold, “On some new Forms of Entozoa,” ‘Linn. Trans.,’ vol. xxii, p. 365, 1859.--Idem, “List of Entozoa,” &c., ‘Proc. Zool. Soc.,’ March 26, 1861.--Idem, “Notes on Entozoa,” part iii, ‘Proc. Zool. Soc.,’ Feb. 1, 1876, p. 202.--Marcgrav, in his ‘Historia rerum nat. Brasil.,’ 1648, p. 226, and in ‘Rudolphi’s Synopsis,’ p. 186.--Molin, “Una Monografia del gen. Spiroptera,” ‘Aus dem Sitzungsb. d. m.-nat. Cl. d. k. Akad. d. Wissensch.,’ Bd. xxxviii, 1859, s. 911, Wien, 1860.--Whitefield, in ‘Edin. New. Phil. Journ.,’ edited by Jamieson, 1829, p. 58.
VIII. (RUMINANTIA)
In the matter of parasites this order of mammalian animals stands second in importance. An entire volume of the dimensions of the present would barely do justice to the subject. Although in the article “Ruminantia” in ‘Todd’s Cyclopædia,’ and in my popular treatise on the mammalia, I have described the oxen (Bovidæ) and sheep (Ægosceridæ) as separate families, I shall here speak of their entozoa together; and, at the same time, I shall introduce occasional reference to the helminths of the antelopes and gnoos (Antilopidæ), also of the giraffes (Camelopardidæ), the deer tribe (Cervidæ), the camels, and the llamas (Camelidæ). The parasites of the last family, however, will necessarily stand somewhat apart.
Almost all ruminants harbor the liver fluke (Fasciola hepatica). This worm has been found in every variety of the common ox and zebu (Bos taurus, var. Indicus), in the sheep, goat, and argali (Ovis aries, Capra hircus, and G. argali), in the antelopes and gazelle (A. dorcas), in red-deer, roe, and fallow (Cercus elaphus, C. capreolus, and C. dama), and in the two-humped camel (Camelus bactrianus). A closely-allied but much larger species of fluke (F. gigantea) infests the giraffe (Camelopardalis). All these animals are more or less liable to suffer from the “rot” which is produced by these flukes. Into the history of the affection the space at my command does not permit me to enter, but as regards the development of the common fluke I believe the following conclusions to be tolerably well founded. I had long entertained the opinion that our common Planorbis plays the rôle of intermediate bearer, and this view has at length received confirmation.
1. The liver fluke, in its sexually-mature state (Fasc. hepatica), gives rise to the disease commonly called rot; this affection being also locally termed coathe (Dorsetshire, Devon), iles (Cornwall), and bane (Somersetshire). In France it is known as the Cachexie aqueuse, and more popularly as pourriture. In Germany the epidemic disease is called egelseuche, and in a more limited sense either die Fäule or die Leberkrankheit.
2. The rot is especially prevalent during the spring of the year, at which time the fluke itself and innumerable multitudes of the free eggs are constantly escaping from the alimentary canal of the bearer. The germs are thus ordinarily transferred to open pasture-grounds along with the fæces of the bearer.
3. As it has been shown by dissections that the liver of a single sheep may harbor several hundred flukes, and as, also, a single adult fluke is capable of throwing off several thousand eggs, it is certain that any rot-affected flock is capable of distributing millions of fluke germs.
4. Such flukes as have escaped the host per anum do not exhibit active powers of locomotion. Their slight contractile movements, however, serve the purpose of concealing them in the grass, and probably aid in the further expulsion of eggs, which pass from the oviduct in single file.
5. After the death of the escaped flukes the further dispersion of the eggs is facilitated by the subsequent decomposition of the parent worm, and also by its disintegration, partly occasioned by the attacks of insects. It has been calculated that the uterus of a full-grown fluke may contain upwards of forty thousand eggs.
6. By the agency of winds, rains, insects, the feet of cattle, dogs, rabbits, and other animals, as well as by man himself, the freed ova are dispersed and carried to considerable distances; and thus it is that a considerable proportion of them ultimately find their way into ponds, ditches, canals, pools of all kinds, lakes, and running streams.
7. At the time of their expulsion the eggs exhibit a finely segmented condition of the yolk. The egg-contents continue to develop whilst outside the parent’s body, the granular matrix finally becoming transformed into a ciliated embryo, which when set free follows the habit of infusorial animalcules in general by swimming rapidly in the water. The escape of the embryo is effected at the anterior pole of the egg-shell, which is furnished with a lid that opens in consequence of the action of prolonged immersion, aided by the vigorous movements of the contained embryo.
8. The ciliated, free-swimming embryo, at the time of its birth, exhibits the figure of an inverted cone, its anterior extremity, which is broad and somewhat flattened, supporting a central proboscis-like papilla. A small pigment spot placed dorsally, and having the form of a cross, is supposed to be a rudimentary organ of vision. After the lapse of a few days the cilia fall off, the embryo then assuming the character of creeping larvæ (planulæ).
9. Notwithstanding its abridged locomotive powers the non-ciliated larvæ sooner or later gain access to the body of an intermediary bearer, within or upon whose tissues it becomes transformed into a kind of sac or sporocyst. In this condition the larva is capable of developing, agamogenetically, other larvæ in its interior. The sporocysts are highly organised, forming rediæ. According to Willemoes-Suhm, the redia of Fasciola hepatica lives on the body of Planorbis marginata. This organised nurse, which is about a line in length, is the Cercaria cystophora of Wagener. The progeny of this redia consists of armed Cercariæ, which after a time quit the nurse to pass an independent existence in the water.
10. In the cases of some species of fluke there is reason to believe that before the Cercariæ gain access to their final or definitive host they re-enter the bodies of the mollusks. This they accomplish by means of a boring apparatus, and having previously cast off their tails they encyst themselves beneath the surface of the skin. In this new situation they develop into the so-called pupa, which is at length passively transferred with the fodder, or drink, to the digestive organs of the host. In the case of Fasc. hepatica, as probably obtains also with many other flukes, I think there can be no doubt that the Cercariæ pass directly into the bodies of ruminating animals. The circumstance that flukes of this species have been found beneath the human skin shows how considerable are the boring powers of the armed Cercariæ.
In regard to the possibilities of fluke development, that will be best understood by glancing at the constitution of the zoological individual. The sum total of the products of a single germ may be tabulated as follows:--
Zoological individual (Fasciola hepatica).
a. Ovum in all stages, } First “biotome.” b. Ciliated free-swimming embryo, } c. Nurse, germ-sac, sporocyst (redia), } Second “biotome.” d. Active, migrating, tailed larva (cercaria), } e. Encysted, resting larva (pupa), } Third “biotome.” f. Sexually-mature fluke (fasciola). }
This is a fair representation of the life-phases of the fluke. The life-phases are rarely less numerous or complicated than here indicated, but Pagenstecher’s researches tend to prove that under certain climatal conditions the number of larval forms may vary considerably. In other words, the fluke individual does not comprise any definite number of “zoöids,” although the kinds of zoöids are limited. I recognise three “biotomes.” The first includes only one temporary, independent life-phase, this is the ciliated animalcule, which I call a “protozoöid.” The second “biotome” may comprise only a solitary simple sporocyst or germ-sac (deuterozoöid), but an almost indefinite multiplication of new and independent germ-sacs, as well as other more highly organised “nurse formations,” may also be developed from the primary sporocyst (secondary and tertiary “deuterozoöid”). The third “biotome” embraces a large but variable number of “tritozoöids” (cercariæ), an equal number, whatever that may be, of “tetartozoöids” (pupæ), and, therefore, also, a similar number of “pemptozoöids” (flukes).
Practically, other curious results arise out of the foregoing considerations. For example, a single sheep may harbor 1000 flukes. Each fluke will develop 10,000 to 40,000 eggs. Each egg may give rise to 370 zoöids. It thus appears that, if all the conditions were favorable, a single fluke might originate between three and four millions of individualised life-forms, whilst the solitary sheep itself would, under the same circumstances, be the means of causing the production of at least 3,000,000,000 fluke zoöids! Happily, no such results as this can possibly occur in nature, since interfering agencies reduce the favorable conditions. However, the balance of parasitic forms from all sources is usually sufficient to destroy thousands of sheep annually. The virulence of rot-epizoöty is entirely due to the presence of conditions favoring the development of fluke larvæ.
As regards the injurious action of this parasite on animals, it is well known that in particular years, in England alone, hundreds, and even thousands, of sheep have been destroyed in a single season. A writer in the ‘Edinburgh Veterinary Review’ for 1861 states that in the season of 1830-31 the estimated deaths of sheep from rot was between one and two millions. This would, of course, represent a money loss of something like four million pounds sterling. As affording additional striking instances of the disastrous effects of rot, I may cite the statements of Davaine. Thus:--“In the neighbourhood of Arles alone, during the year 1812, no less than 300,000 sheep perished, and at Nimes and Montpellier 90,000. In the inner departments, during the epidemic of the years 1853-54, many cattle-breeders lost a fourth, a third, and even three fourths of their flocks.” In like manner our English authority, Prof. Simonds, furnished a variety of painful cases. Thus, on the estate of Mr Cramp, of the Isle of Thanet, the rot epidemic of 1824 “swept away £3000 worth of his sheep in less than three months, compelling him to give up his farm.” Scores of cases are on record where our English farmers have individually lost three, four, five, six, seven, and even eight hundred sheep in a single season; and many agriculturists have thus become completely ruined.
Remarkable periodic outbreaks of this disease are recorded by Simonds as occurring in England in the successive years of 1809, ’16, ’24, ’30, ’53, and ’60; whilst, for France, Davaine mentions 1809, ’12, ’16, ’17, ’20, ’29, ’30, ’53, and ’54, as the most remarkable years. It would be interesting to know how far these outbreaks tally with the similar outbreaks which have occurred in Holland, Germany, and other European districts. The disease was prevalent during four separate years in France and England at one and the same time. This, indeed, is no more than we would naturally expect, considering that the extent of the development of the larval forms must, in a great measure, be dependent upon atmospheric conditions. A warm and moist season would alike prove beneficial to the development of the larvæ and their intermediate molluscan hosts. Their numbers would also multiply enormously; for, as already remarked, the degree of non-sexual production of trematode larvæ within their sporocysts is materially affected by climatic changes. On the other hand, a fine, dry, open season will tend to check the growth and wanderings of the larvæ, and thus render the flocks comparatively secure.
Considerations like these sufficiently explain many of the crude theories which were early propagated concerning the causes of this disease, and in particular, the very generally prevalent notion that water, and water alone, was the true source of the disease. Intelligent cattle-breeders and agriculturists have all along observed that the rot was particularly virulent after long-continued wet weather, and more especially so when there had been a succession of wet seasons. They have likewise noticed that flocks grazing in low pastures and marshy districts were much more liable to invasion than sheep which pastured on higher and drier grounds, but noteworthy exceptions occurred in the case of flocks feeding in the salt-water marshes of our eastern shores. The latter circumstance appears to have suggested the common practice of mixing salt with the food of sheep and cattle, both as a preventive and curative agent; and there can be little doubt that this remedy has always been attended with more or less satisfactory results. The intelligible explanation of the good effected by this mode of treatment we shall find to be intimately associated with a correct understanding of the genetic relations of the entozoon, for it is certain that the larvæ of Fasciola hepatica exist in the bodies of fresh-water snails. As already hinted from Willemoes-Suhm’s observations, it is not improbable that the larvæ are confined to gasteropod mollusks belonging to the genus Planorbis.
The symptoms produced by rot are very striking. When the disease has far advanced it is easy to know a rotten sheep, not only by its very look, but still more convincingly, as I have myself tested, by slightly pressing the hand over the region of the loins. In this region the diseased animal is particularly weak, and the pressure thus applied instantly causes it to wince. At the same time the hand feels a peculiar sensation very unlike that communicated by the spine of a sound animal. In bad cases the back becomes hollow, and there is a corresponding pendulous condition of the abdomen. The spinal columns ultimately stick out prominently, forming the so-called “razor-back.” As Professor Simonds has well observed, in an earlier stage of the disease, “an examination of the eye will readily assist in determining the nature of the malady. If the lids are everted it will be found that the vessels of the conjunctiva are turgid with pale or yellowish colored blood, the whole part presenting a peculiar moist or watery appearance. Later on, the same vessels become blanched and scarcely recognisable.” The skin also becomes harsh and dry, losing its natural tint, and the wool is at length rendered brittle, either becoming very easily detached or falling off spontaneously.
The first thing noticeable in dissecting a rotten sheep is the wasted and watery condition of all the tissues. There is a total absence of that firm, fresh, carneous look which so distinctively characterises the flesh in a state of health. Not only is the rigidity and firm consistency of the muscles altogether wanting, but these structures have lost that deep reddish color which normally exists. When the abdominal cavity is opened a more or less abundant, clear, limpid, or yellowish fluid will make its escape, and the entire visceral contents will, at the same time, display a remarkably blanched aspect. These pathological changes are also shared by the important organ especially affected, namely, the liver. This gland has lost its general plumpness, smoothness, and rich, reddish-brown color, and has become irregularly knotted and uneven both at the surface and the margins, its coloring being either a dirty chocolate brown, more or less strongly pronounced at different parts, or it has a peculiar yellowish tint, which in places is very pale and conspicuous. To the feel it is hard and brawny, and when incised by the scalpel, yields a tough and, in places, a very gritty sensation. On opening the gall-ducts a dark, thick, grumous, biliary secretion oozes slowly out, together with several distomes, which, if not dead, slowly curve upon themselves, and roll up like a slip of heated parchment. On further slitting open the biliary passages, they are found distended irregularly at various points, and in certain situations many flukes are massed together, having caused the ducts to form large sacs, in which the parasites are snugly ensconced. The walls of the ducts are also much thickened in places, and hardened by a deposit of coarse calcareous grains on their inner surface. Mr Simonds says, that the “coats of the ductus hepaticus, as also of the ductus communis choledicus, are not unfrequently so thick as to be upwards of ten times their normal substance, and, likewise, so hard as to approach the nature of cartilage.” Respecting their numbers, the greatest variation exists. The presence of a few flukes in the liver is totally insufficient to cause death; consequently, when a sheep dies from rot, or is killed at a time when the disease has seriously impoverished the animal, then we are sure to find the organ occupied by many dozen, many score, or even several hundred flukes. Thus from a single liver Bidloo obtained 800, Leuwenhoeck about 900, and Dupuy upwards of 1000 specimens. Even the occurrence of large numbers only destroys the animal by slow degrees, and, possibly, without producing much physical suffering, excepting, perhaps, in the later stages. Associated with the above-described appearances, one also not unfrequently finds a few flukes in the intestinal canal, whilst a still more interesting pathological feature is seen in the fact that the bile contained in the liver ducts is loaded with flukes’ eggs. In some cases there cannot be less than tens or even hundreds of thousands. Not a few may also be found in the intestinal canal and in the excrement about to be voided. Occasionally dead specimens become surrounded by inspissated bile, and gritty particles deposited in the liver ducts, thus forming the nuclei of gall-stones. Mr Simonds mentions a remarkable instance, “where the concretion was as large as an ordinary hen’s egg, and when broken up was found to contain about a dozen dead flukes. It was lying in a pouch-like cavity of one of the biliary ducts.”
In respect of treatment we all know that “prevention is better than cure.” Moisture being essential to the growth and development of the fluke-larvæ, it is clear that sheep cannot be infected so long as they remain on high and dry grounds, and even in low pastures they can scarcely take the disease so long as they are folded, and fed on hay, turnips, and fodder procured from drier situations. When once the malady has become fairly developed, internal remedies are of little avail, at least, in view of producing a thorough cure. Palliative treatment may undoubtedly do good, especially in cases where the disease is not very strongly pronounced. The most important thing is the transference of the rot-affected animals to dry ground and good shelter, supplying them, at the same time, with a liberal quantity of manger food, such as beans, peas, and other leguminous seeds. The fodder, of whatever kind, should be frequently changed, and many other hygienic measures adopted, all tending to promote the appetite and general health of the animal. An admixture of salines is a matter of essential importance, especially in cases where the disease is not far advanced. The beneficial effect of salt is one of those few points on which nearly all parties are agreed, and its preservative influence in the case of sheep fed upon salt-water marsh-land has been previously explained. In regard, however, to the legion of remedies which have from time to time been proposed, all I need here say is, that most of them when fairly tested have been found to fail ignominiously. Every year we hear of the adoption, often with enthusiasm, of new so-called specifics, or of ancient medicines whose employment had long fallen into disuse. Thus, for example, in the April number of the ‘Journal des Vétérinaires du Midi’ for 1860, we find M. Raynaud strongly recommending soot, in doses of from one to three spoonfuls, to be followed up by the administration of a grain of lupin for tonic purposes. In like manner, we received from France wonderful accounts of the medicinal virtues of a certain fœtid oleaginous compound, the value of which was put to a fair test by our distinguished veterinarian, Professor Simonds. Having with infinite care and trouble undertaken a series of experiments with the remedy in question, Mr Simonds writes in the ‘Scottish Farmer and Horticulturist’ to the effect that, as a result of his inquiries, he fears “we must conclude that this supposed cure of rot in sheep has proved quite ineffective for good.” The last new “cure” announced is by Mr Robert Fletcher (‘Journ. Nat. Agric. Soc. of Victoria,’ Dec., 1878).
The examination of rotten sheep is not altogether free from danger. Professor Simonds tells us that in August, 1854, “a person of intemperate habits, following the occupation of a country butcher, was employed in skinning and dressing a number of rotten sheep on the premises of a farmer in the county of Norfolk. The sheep were necessarily opened when warm, and while he was so engaged he complained greatly of the sickening smell. The same evening he was attacked with choleraic disease, and two days afterwards was a corpse.” This case is highly instructive and, when taken in connection with the well-known fact that animals affected with the disease putrefy very rapidly, clearly points to the necessity of removing slaughter-houses far away from densely populated localities.
Notwithstanding the above statement, there is little or no danger to be apprehended from the consumption of the flesh of rot-affected animals. On this vexed question we have the strong testimony of the late Dr Rowe, of Australia, who, after leaving the medical profession, became a large and successful stockowner, and devoted himself especially to this question. Dr Rowe, writing from the Goulburn district, said:--“The mere presence of flukes in the viscera of an animal is no proof that it is unfit for human food. For inspectors of slaughter-houses to adopt such a test of wholesome food would be the greatest mistake. It would afford no protection to the public against unhealthy food, would increase the price of animals, and be ruinous to our farmers and graziers. If the consumption of flukey beef and mutton were prejudicial to the health of man, there would be very few people alive in this part of the colony; for, to my certain knowledge, they have had no other animal food to live upon for the last twenty-five years, yet for physical ability I believe they may be favorably compared with the inhabitants of any other part of Australia.” Speaking of his own experiences, Dr Rowe avers that he found the common liver fluke in sheep, cattle, goats, opossums, kangaroos, geese, ducks, and other creatures, but he had never encountered it in men, dogs, or pigs. On the whole I think we may agree with Dr Rowe, in regarding the consumption of the flesh of rot-affected animals as free from danger provided only the meat, be well or even moderately well cooked. It must be borne in mind, however, that an essential objection to its consumption lies in the fact that the watery and otherwise chemically deteriorated flesh is comparatively innutritious. It must also be noted that the meat-supply from fluke-affected animals, as usually sold in the markets, is chiefly derived from animals which have only entered the early stage of the disorder, that is, long before the watery and wasted condition of the muscles has fairly set in.
Respecting the other trematodes I have to observe that Distoma lanceolatum not only infests the liver ducts of cattle and sheep, but also the deer tribe. Its larvæ are likewise supposed to reside in Planorbis marginatus. Still more common and widespread amongst ruminants is the Amphistoma conicum, occupying the paunch. It has been found in the ox, sheep, musk-ox, elk, roe, fallow, red-deer, goat, and dorcas-antelope; also in Cerrus campestris, C. nambi, C. rufus, and C. simplicicornis. Prof. Garrod has also recently shown me examples from the sambu deer of India (C. Aristotelis). Diesing’s A. lunatum, infesting Cerrus dichotomus, is inadmissible. Two other species of Amphistome (A. explanatum, A. crumeniferum) are said to infest the zebu; and I have described another (A. tuberculatum) from the intestines of Indian cattle. An aberrant amphistomatoid entozoon (Gyrocotyle rugosa) has been found in a Cape antelope (A. pygarga). Of more interest, however, is the circumstance that Dr Sonsino has discovered a species of Bilharzia (B. bovis) in Egyptian cattle and in sheep. The eggs of this species are distinctive, being fusiform and narrowed towards either pole.
Comparatively few tapeworms are found in ruminants. Cattle are infested by Tænia expansa and T. denticulata, the former of these two species being also more or less prevalent in sheep, antelopes, and deer. Other alleged species (Tænia fimbriata and T. capræ) appear to me more than doubtful. Unquestionably the common Tænia expansa is capable of giving rise to severe epizoöty among lambs. The privately communicated evidence of Professors Brown and Axe, and published evidence supplied by Messrs Cox and Robertson on this head, are conclusive. Mr George Rugg has also (in a letter to Prof. Simonds, dated Dec. 4th, 1878) communicated the particulars of an outbreak in which “large numbers of lambs perished rapidly” from tapeworms in the intestines, the parasites varying from one to five or six feet in length. This tapeworm (T. expansa) is also very prevalent in Germany. Ruminants, however, both at home and abroad, suffer much more severely from bladder-worms. Of these, Echinococcus veterinorum, Cysticercus tenuicollis, and Cœnurus cerebralis, are not only shared alike by all varieties of cattle, sheep, and goats, but they also infest the deer tribe, antelopes, the giraffe, and even camels. In 1859 I obtained the slender-necked hydatid from a spring-bok (Gazella). Besides these larval cestodes, cattle are very liable to harbor measles (Cysticercus bovis), whilst sheep also entertain an armed Cysticercus (C. ovis). I cannot again dwell at any length upon the source of these immature helminths, but I may remark upon the extreme frequency of measles in Indian cattle. This is explained by the careless habits of the people. They not only consume veal and beef in an imperfectly cooked state, but when suffering from tapeworm no precautions are taken to prevent cattle from having access to the expelled proglottides of Tænia mediocanellata. The subject has already been dealt with in the first part of this work, and also in my ‘Manual,’ quoted in the bibliography. The mutton measle is described under the heading of Tænia tenella. In like manner I must refer to the ‘Manual’ for a detailed account of the gid hydatid (Cœnurus cerebralis). How many kinds of Cœnuri exist it is impossible to say, but I am of opinion that the various polycephalous bladder-worms found by Rose, Baillet, and Alston in rabbits, by myself in a lemur and in a squirrel, and by Engelmeyer in the liver of a cat, are referable to tapeworms specifically distinct from the Tænia cœnurus of the dog.
It was in 1833 that Mr C. B. Rose, formerly of Swaffham, Norfolk, discovered an undoubted example of polycephalous hydatid in the rabbit, the parasite in question bearing a very close resemblance to Cœnurus cerebralis. As the accuracy of Rose’s determination respecting the characters of the hydatid has been called in question, I again invite attention to the original description as recorded in the ‘London Medical Gazette’ for November 9th, 1833. At page 206, vol. xiii, of that periodical, after describing the common Cœnurus cerebralis of the sheep, Rose writes:--“This (i.e. C. cerebralis) is the only species of Cœnurus noticed by authors, but I have met with another. It infests the rabbit, and I have found it situated between the muscles of the loins. It is also met with in the neck and back. This hydatid grows rapidly, and multiplies prodigiously, and being seated near the surface it soon projects, and sometimes forms a tumour of considerable magnitude. When the warrener meets with a rabbit thus affected, he punctures the tumour, squeezes out the fluid, and sends the animal to market with its brethren. I possess a specimen of this species in a pregnant state. The earliest visible state of gestation is a minute spot, more transparent than the surrounding coats of the parent; this enlarges till it projects from the parietes of the maternal vesicle. It continues to enlarge until it becomes a perfect hydatid, attached by a slender peduncle only; even whilst small, other young are seen sprouting from it, and so on in a series of three or four. My specimen exhibits them in every stage of growth, from a minute point to a vesicle the size of a hen’s egg. As I can see no difference in structure between this hydatid and the last-mentioned (i.e. Cœnurus cerebralis), I am unwilling to consider it a different species, for surely a varying locality ought not to constitute a specific character.”
The observations of Rose did not escape the well-known Dutch author, Numan. In a foot-note to his memoir, entitled “Over den veelkop-blaasworm der Hersenen,” he makes the following observations:--“Rose observes that he has found Cœnurus in bladdery rabbits (blaaszieke konijnen) in the skin, and in the cellular tissues of the trunk and extremities. The veterinary surgeon, Engelmeyer, of Burgau, says he has also found the Cœnurus (Veelkop) in the liver of a cat (‘Thierärztliche Wochenschrift van 1850,’ s. 192). These observations differ thus far from those of other writers, according to whom the Cœnurus is only found in the brain and spinal marrow. However, it is not impossible in particular cases that some parasites may have strayed from their ordinary dwelling-places.” Numan seems to have been not a little puzzled to account for these discrepancies, and he was altogether undecided regarding the mode of propagation of Cœnuri and Cysticerci. This will be gathered from the following passage, which I quote in the original:
“Ik moet het onbeslist laten, of de grondbeginsels, waaruit de wormen uit de blaas ontspruiten, als wezenlijke of als zoogenaamde kiemen (gemmæ) zijn te houden, waaromtrent de gevoelens der voornamste Natuuronderzoekers, die zich met de nasporing der blaaswormen hebben onledig gehouden, nog uiteenloopen. Gulliver, door Rose (a. p. pag. 231) aangehaald, houdt ze voor eijeren, in den Cysticercus tenuicollis, en Goodsir, mede aldaar genoemd, spreckt ook van ova bij den Cœnurus cerebralis; doch de laatstgenoemde en Busk houden ze voor gemmæ. Hier wordt voots gewezen op Owen en de meeste onderzoekers van den tegenwoordigen tijd, die het daarvoor houden, dat alle hydatiden zich alleen door gemmæ reproduceren. Rose merkt voorts aan, dat, hetzij men de geboorte dezer ingewandswormen toekenne aan eijeren of kiemen (gemmæ), dit om het even is, wat hunne verspreiding (dissemination) betreft, daar zij ingesloten zijn, waardoor de wijze, hoe zij naar buiten komen en verspried worden, tot dusver een gesloten boek is.”
The idea of Numan that these are strayed forms of Cœnurus cerebralis is not convincing. It must not be forgotten, however, as Leuckart and Numan have both reminded us, that Eichler discovered an hydatid about the size of a goose egg in the subcutaneous tissue of a sheep. This bladder-worm supported nearly two thousand heads. In regard to true hydatids or acephalocysts in ruminants, on which subject I have already dwelt at much length, I may again observe that the Hunterian Museum contains some remarkable examples. In 1854 I obtained Cysticerci from a giraffe, and I have reason to believe that similar bladder-worms infest antelopes and deer.
The nematodes of the ruminants are both numerous in, and destructive to, their bearers, those infesting the lungs being productive of a parasitic bronchitis termed husk or hoose. In cattle the lung-worm (Strongylus micrurus) is particularly fatal to calves, whilst S. filaria attacks sheep, and especially lambs. A larger but less common lung strongyle (S. rufescens) is sometimes found associated with the latter. In 1875 I conducted experiments with the view of finding the intermediate hosts of S. micrurus, and I arrived at the conclusion that the larvæ of this parasite are passively transferred to the digestive organs of earth-worms. The growth and metamorphoses which I witnessed in strongyloid larvæ taken from earth-worms (into which I had previously introduced embryos) were remarkably rapid, and accompanied by ecdysis. The facts were as follows. About the middle of October, 1875, I received from Messrs Farrow, of Durham, a fresh and characteristic specimen of diseased lungs, in which the bronchi were swarming with Filariæ.
In reference to the case itself, Mr George Farrow afterwards informed me by letter that the calf was one of a herd of seven, whose ages respectively varied from four to six months. At the time of his writing (October 20th) the remaining six animals were progressing favorably towards recovery--a result which Mr Farrow attributes to the employment of inhalations of turpentine and savin, combined with the internal administration of tonics. In regard to this plan of treatment, and in reference to the source of infection, he adds:--“I should have preferred trying the inhalations of chlorine gas, but as the patients were so very young and in poor condition, I deemed it advisable to try a milder course of treatment.
“The history of the case is brief. The cattle are on a very dry and well-drained farm, but during the summer there was a great scarcity of water, and they were supplied from a stagnant pool which eventually became dry. This, in my opinion, is where the disease originated.”
Mr George Farrow’s opinion is probably correct, being in harmony with the most recent results of scientific research as made known more particularly by Leuckart. But the facts thus conveyed do not explain the whole truth; or, rather, they convey it only in a very incomplete manner. Professor Leuckart’s experiments were made with several species such as Strongylus armatus of the horse, S. rufescens, S. hypostomus, and S. filaria of the sheep, and S. commutatus of the hare. Still, as regards the strongyles, partial as the results have thus far appeared, there cannot be a doubt that his successes with several allied nematode species form a key by which we may yet unlock and expose to view the entire life-history of that specially obnoxious form under consideration, namely, Strongylus micrurus. To summarise the whole matter in a few words, Leuckart supposes that all these strongyloids require a change of hosts before they can take up their final abode in the sexually-mature state. This he infers especially because their respective embryos display characters very similar to those exhibited by Olulanus. He believes that either small mollusks or insects and their larvæ play the rôle of intermediary bearer. His experiments with the embryos of Strongylus filaria prove that these larvæ can be kept alive for several weeks in moist earth, and that whilst so conditioned they undergo a first change of skin within a period varying from eight to fourteen days. Experiments on sheep, made with these moulting larvæ, led only to negative results. Unless the following facts be accepted, the scientific position remains pretty much where Leuckart left it.
On the 22nd of October, 1875, at 1 p.m., I placed the entire egg-contents of the uterus of a Strongylus micrurus on a glass slide hollowed out in the centre. Probably something like ten thousand ova were thus brought under observation, yet only three were noticed as freed from their shells, probably as the result of accidental rupture. Two of these displayed lively movements. In round numbers the ova gave a measurement of 1/300 of an inch in length by 1/750 of an inch in breadth, whilst the free embryos measured about 1/90 of an inch long, and less than 1/1000 of an inch in thickness. The integument of the embryo displayed neither markings of any kind nor any double contour. The contents of the worm were granular throughout, these granules being crowded in the centre of the body, but scarcely visible towards the head and tail, where for a considerable space (fully 1/300″) the worm was perfectly transparent. No trace of any sexual organs or their outlets was visible. An examination of numerous eggs and free embryos obtained from near the primary bronchial bifurcations (of Mr Farrow’s specimen) yielded the same microscopic results, the only thing worthy of remark being that the embryos from the mucus seemed much more lively than those which, as I supposed, had accidentally escaped their shells.
At 1.30 p.m. I placed some free embryos in two watch-glasses, one containing water and the other saliva, and placed them before the fire. Being called away professionally I found on my return at 3 p.m. that evaporation to dryness had occurred in the interval. All my attempts to resuscitate the embryos by moisture proved unavailing, a result which, though negative, proves how little capable these embryonic creatures are of enduring desiccation. If these facts be confirmed, their practical significance is not without value in relation to the choice of dry pasturage grounds for the rearing of young cattle. I may add that whilst half an hour’s immersion of the dried embryos failed to restore any sign of life, the previous warmth and moisture had caused many more embryos to escape their shells during the time they were placed before the fire.
At 4 p.m. I passed some very rich mould through muslin. Some of this finely sifted earth I placed in a watch-glass, adding a little water to moisten it, and also numerous eggs and free embryos. In a wine-glass and also in a small jar I placed some coarse earth with water added to make thin mud, and to both of these I added, not only eggs and embryos, but also portions of the reproductive organs of the adult female worms.
On the 23rd of October, at 2 p.m., I examined the contents of these vessels. All the embryos in the vessels containing the coarse earth were dead, but several were found alive in the watch-glass containing the fine moist mould. Structurally these latter had undergone no perceptible change beyond a somewhat closer aggregation of the somatic granules.
Although the embryos in the coarse wet mud had perished, the eggs with unhatched embryos appeared to have retained their vitality. Of this fact, indeed, I subsequently obtained abundant proof; and I also satisfied myself that the death of the embryos had not resulted either from the coarseness of the earth or from excessive moisture, but from the presence of numerous shreds of the uterine tubes which I had somewhat carelessly added to the vessels. Previous experiments, conducted many years back, had indeed taught me that few if any nematoid larvæ can resist the fatal action of putrid matter, however slight the putrescence.
Having removed the offending shreds, I next placed a quantity of living ova together in the earthenware jar, and allowed the earth-contents to become much drier by evaporation before the fire. I also left others in a watch-glass, which was placed under a bell-jar enclosing several ferns.
On the 25th of October I removed particles of the moist earth, altogether weighing about two grains, and, on submitting them to microscopic examination, had the satisfaction to observe about a dozen living embryos, some of which exhibited very lively movements. There was not the slightest indication of putridity; nevertheless, I noticed several shreds of the adult worms whose presence had been accidentally overlooked, and, curiously enough, all the embryos subsequently removed from the immediate neighbourhood of these decomposing shreds of tissue were almost motionless and apparently in a moribund condition. On examining the contents of the watch-glass placed under the fern shade, I noticed several points of interest. First of all the earth contained strongyle embryos, such as I had seen before. Secondly, the surface of the mould was being traversed by three or four briskly-moving Thysanuridæ, hunting about with all that restless activity which Sir John Lubbock has so well described. Thirdly, in marked contrast to the behaviour of these I noticed several slow-moving Acaridæ, apparently also employed in searching for food. And lastly, while thus engaged, the surface of the mould in the centre of the deep watch-glass was suddenly upheaved, by which I was at once made aware of the presence of another most welcome and unexpected intruder. In short, an earth-worm had crept from the dry mould in which the ferns were growing, and had taken up its temporary abode in the soft moist experimental-earth contained in the watch-glass. When contracted, this Lumbricus terrestris was barely an inch in length. On placing it under the half-inch objective glass, I noticed a single embryonic strongyle adhering to the skin, but not firmly, and evidently only in an accidental way, so to speak. It was clear to me that it possessed neither the intention nor the power to penetrate the chitinous integument of the earth-worm.
Having in the next place removed the Lumbricus with a pair of forceps, and having washed it under a current of water, I snipped off the lower end of the body, and allowed some of the intestinal contents to escape on a clean glass slide for separate microscopic examination. Immediately, to my satisfaction, I found that the fæcal contents displayed a large quantity of my strongyle ova, enclosing still living embryos, and in addition several free embryos presenting characters which declared that they were from the same source. Clearly they had been ingested by the earth-worm along with its ordinary food. One or two of the embryos were conspicuously larger than their fellows, but the structural changes they had undergone were not so marked as to lead me for a single moment to associate them with any of the various sexually-mature worms which have been described as normally infesting the earth-worm. I had no doubt whatever that such slight structural changes as were now discernible had resulted from growth and development consequent upon this accidental admission into the body of the intermediate bearer which might or might not prove to be its legitimate territory. It will be seen that subsequent observations tended to affirm the truth of this view. I made a careful examination of one of these larvæ, whose active movements were such as to render the process exceedingly tedious. The earth-worm itself (or rather its unequal halves) was placed in a fresh watch-glass containing ordinary mould. The larvæ or embryos obtained from the earth-worm now measured about 1/80 of an inch in length, their heads exhibiting a short and simple chitinous buccal tube, whilst their tails were somewhat more pointed and bent upward. The somatic granules were more crowded, rendering the position of the intestinal tract more marked, though, as yet, the differentiation gave no indication of the formation of a distinct intestinal wall. There was no perceptible increase of thickness of the body of the embryos. The results thus far naturally encouraged me to procure some fresh earth-worms for experimental purposes.
On the 26th of October I found that the halves of the earth-worm were alive, and I left them undisturbed in rather dry mould, freshly added. To a watch-glass containing newly sifted earth and embryos I added a fresh garden-worm, which was rather sluggish from the cold; and in the original jar I placed another smaller and very active earth-worm obtained the same morning. Finding the soil in the jar congenial, this lumbricus soon buried itself. Another and larger earth-worm subsequently added refused to follow this example. It was therefore removed from the jar. Believing the fine and artificially prepared soil to be still much too moist, I caused further evaporation; and I afterwards found that the thicker the mud the more suitable it proved as a residence for embryonic nematodes and earth-worms alike.
On the 27th I found the small earth-worms in the jar burrowing freely and throwing up fæcal casts. From one of my watch-glasses the worm had escaped, its place being occupied in the meantime by an actively crawling Julus. I put a second Julus, obtained from the mould in the fern jar, to form a companion (in view of other experiments), and I also added a fresh earth-worm, covering all by another inverted watch-glass, which I thought would prevent their escape.
In the next place I examined the halves of my original experimental earth-worm. They were scarcely capable of motion, but retained a certain amount of vitality. The tail was the more active half, and unfortunately it was soon afterwards lost. Carefully washing the superior half, and transferring its contents to a glass slide, I immediately detected under the microscope a large number of embryos. They were in a state of marked activity, the largest having increased to about 1/50″ of an inch in length, whilst their structure had become correspondingly advanced. Here, again, there was no room for doubt as to their source, especially as they individually displayed different degrees of organisation, all answering to one and the same embryonal type. I now observed a distinct œsophagus, the rest of the intestinal tract being still more conspicuous than heretofore, though, as yet, no true cells marked the limitation of the stomach and chylous intestine.
After an hour’s immersion in cold water some of the larvæ became much less active, whilst others were motionless, so that I feared all were about to perish. In the hope of keeping a few of them alive I now added to the slide some finely sifted grains of mould, placing the slide under a small bell jar which protected some of my ferns. The remains of the moribund earth-worm were also covered with mould.
Other larvæ, derived from the earth-worm, were placed on the moist pinnæ of a living fern-frond which supported small drops of water, for by this process I hoped in some measure to imitate the dew which naturally condenses on the grass and fodder of our low-lying fields. At 3.15 p.m. of the same day (27th) I also examined a fresh worm pellet from the jar, and found it to contain living strongyle embryos, which as heretofore had not exhibited the slightest advance either in respect of size or structure.
At noon on the 28th I again sought for the larger larvæ, first of all on the slide covered with fine earth, and afterwards within the remains of the upper half of the original earth-worm. On the slide I could detect none, but within the intestine of the worm there were still two living larvæ left, whose characters corresponded precisely with the largest that I had previously obtained from the same source only the day before. They had undergone, however, no further change in structure, and their measurements remained precisely the same.
At 12.30 p.m. I snipped off two or three of the terminal fern-fronds on which I had placed a few advanced larvæ. On examination under the half-inch objective I immediately detected one of the larvæ cruising about most actively. On adding a drop of water it soon rushed across the field of the microscope, its movements being thoroughly eel-like. The size of this larvæ had so much increased that it was now visible to the naked eye, measuring, indeed, as much as 1/30 of an inch from head to tail. Moreover, its organisation had advanced in a marked degree. Thus, the digestive organs were better defined, and on one side of them there appeared a regularly arranged congeries of cellules, forming the commencement of the reproductive organs. As yet, however, I could not pronounce as to the sex.
At 1.45 p.m. I again examined a few grains of earth from the jar, when I at once noticed five or six active embryos whose structure failed to show the slightest advance upon that originally described. It was evident that the jar contained thousands of them; and since no ova were found, it became probable that all their embryonic contents had escaped to swell the number of free larvæ, leaving their very delicate envelopes to perish. I think I had hit upon the most suitable degree of moisture favorable to this result.
In the next place I sought for the earth-worm that had been placed in the infested soil between two watch-glasses. It had escaped. This obliged me to transfer the mould to a rather wide-mouthed and open phial, in which four more fresh lumbrici were placed. I feared the closing of the bottle would be detrimental.
Later in the day I selected an earth-worm which had not been exposed to strongyle infection, but which was in a moribund condition. In the intestine there were several free nematoids and also several psorosperms of the genus Monocystis, so well illustrated by E. Ray Lankester. As to the nematoids, which were filariform, they neither corresponded in size nor structure with my strongyle embryos.
At 1 p.m. on the 29th I renewed my examination of the larva removed from the fern-pinnule. It showed a further stage of growth, the male character of the reproductive organs having become apparent. The now tolerably well-formed vas deferens had pushed the chylous intestine on one side, whilst a series of caudal rays, five on either side, supported two narrow membranous wings, which represented the lateral lobes of the hood of the adult strongyle.
At 1.30 p.m. I submitted the intestinal contents of four fresh earth-worms removed from my garden to microscopic examination, but no nematoids were found in any one of them.
About 2 p.m. I removed another large and active strongyle larva that had been reared on another fern-pinnule. It was of the same size as that previously described, but was in the act of changing its skin. It was then put aside along with the other worm under the glass shade.
At 3 p.m. I intended to have examined one or more of the earth-worms placed in the open-mouthed phial, but all had escaped and buried themselves in the fern-mould out of reach.
At noon on the 30th I renewed my examination of the two large larvæ whose developmental changes I had been instrumental in producing from the time of their escape from the egg-coverings. I saw no reason to doubt that the sequence of changes thus far noticed referred to the species of parasite under consideration. Both larvæ were active, but the moulting one had now completed its ecdysis. Its sexual distinctiveness had become yet more pronounced by the formation of two rather short and stout spicules, the point of the tail displaying a very minute awl-shaped projection. The lateral membranes had not visibly increased in size. One of these larvæ, the first under observation, now perished from the injuries sustained during inspection.
Again, and later in the day, I sought to clear up any doubts that might still suggest themselves respecting the source of these larvæ, by once more submitting the intestinal contents of two fresh and uninfected earth-worms to careful scrutiny. In the first worm no parasite could be found, and in the second only one minute nematoid; its organisation, which was sexually incomplete, neither corresponded with my strongyle embryos, nor, so far as I could judge, with Goeze’s Ascaris minutissima microscopica (the Anguillula lumbrici of Diesing and others), nor with Dujardin’s Dicelis filaria. It was a very long and narrow creature, but I lost it whilst attempting to secure an accurate measurement. I should say it was about 1/50th of an inch in length, and not more than 1/1500th in breadth. I made a rough outline sketch of it.
In view of further observations I now placed five more earth-worms in the jar containing strongyle embryos, and I also placed six others in the phial which contained coarser mould, and only a comparatively small number of the original strongyle embryos. The phial was closed with a cork and half buried in the fern-mould of one of my larger Wardian fern-pans. Before this transfer was made I again took an opportunity of ascertaining by microscopic evidence that the embryos lodged in the coarse and fine mould had none of them made the slightest advance in organisation. The worms placed in the jar immediately proceeded to bury themselves.
At noon on the 1st of November I sought to get further results from the only large free larva which now remained to me (for the fern-pinnules on which the larvæ were originally placed had dried up and no third specimen could be discovered). Structurally the larva presented no advance. It therefore appeared to me necessary to place it under new conditions in view of exciting further progress towards sexual maturity and adult growth. To transfer it to the bronchus of a living calf would, of course, have been the crucial experiment, but the hopelessness of getting any satisfactory result from this solitary transfer deterred me from the attempt. On a larger scale, with many larvæ, a positive issue would of course prove decisive. Accordingly, the only thing I could do, in partial imitation of nature, was to try and induce some further changes by placing the larva in human saliva, kept warm artificially. As a first step I immersed the creature in a little of the secretion added to the glass slide, when it immediately displayed very lively movements, such as could only be fitly described as frantic. This encouraged me to replace the slide under one of the fern shades without applying any additional heat. I then left it.
At 12.30 p.m. I selected three of the eleven worms lodged in the infested earth, namely, two from the jar and one from the closed phial, and made a microscopic examination of their respective intestinal contents. In one of the worms from the jar I found several embryos clearly referable to my strongyles, their structure showing scarcely any advance upon that exhibited by the embryos in the mould itself. The weather was now excessively cold and the larvæ were motionless; nevertheless, the application of warmth showed that they were by no means dead. The fæcal matter obtained from the worm that had lived in the phial displayed an immense number of infusoriæ (Bacteria) which rushed about rapidly over the field of the microscope. No other signs of life were detected.
On the 2nd of November I found my solitary strongyle larva alive, but its movements, though active, were by no means so active as on the previous day. No fresh structural changes had occurred.
At noon on the 3rd the larva at first lay almost motionless in the now thick and ropy saliva; nevertheless, on applying a thin glass cover its movements became tolerably vigorous. During its quiescent state I succeeded in getting a good view of the caudal rays and other imperfectly developed organs, of which I retain figures.
Having now satisfied myself that other new conditions were necessary to enable the larva to arrive at sexual maturity, I sought to transfer it to a glass tube filled with fresh saliva. This transfer was a matter of difficulty. After passing the thick ropy saliva into the tube, I examined the slide and found that the larva was gone. I concluded it was in the tube, which, in order to keep the contents warm, I subsequently carried about concealed in my under-clothing during the day and placed in my bed during the night. This increase of temperature, however, caused decomposition of the saliva; so when next day I diligently sought for my experimental nematode it was nowhere to be found. Thus terminated my observations on the first set of embryos, which had enjoyed their temporary sojourn in the intestinal tract of the earth-worm, and which had certainly afterwards undergone a series of marked structural and morphological changes, accompanied with ecdysis.
The weather had now been for several days exceedingly cold, but on the 4th a favorable change set in, which led me to hope that I might be able to verify the facts above recorded. Accordingly, as a new point of departure, I re-examined the fine mould, and at once found my embryos in a high state of activity. The mould, however, appearing too moist for the earth-worms, I permitted further evaporation before closing the jar with a glass cover. Four days subsequently I examined the intestinal contents of two of the earth-worms. In one of these, an inch in length, no parasite of any kind could be detected; but in the other, which was beyond three inches in length, there were numerous Opalinæ besides several strongyle embryos, the latter presenting characters not visibly in advance of those still living in the mould. All of them were motionless, as if they had not got over the shock produced by previous cold. Moreover, the weather had again become cold, and thus, when I again inspected my experimental embryos living in the jar, I also found them motionless, so different from their behaviour on the 4th. However, since a further result with the earth-worm embryos appeared possible, I placed some of the fæcal matter, already ascertained to contain a few of them, on the fronds of a thoroughly moist and dew-covered Asplenium bulbiferum. This plant was in a fern-pan which had the advantage of considerable fire-warmth during the day. When, however, on the 15th of November, I examined the fæcal earth removed from several of the pinnules, I failed to find any of the embryos. Possibly they had wandered, for the entire frond was covered with dew-drops, which was not the case with the fern that I had previously experimented on with such satisfactory results. At all events, whether they had wandered or had perished, their apparent absence in no way affects my previous record; and the more so since only a few had been observed in the fæcal matter. The smallness of the number found in the earth-worm was also readily accounted for. Thus, when at 1.30 p.m. on the 15th I made a diligent search for embryos in several grains of the fine mould, not a single young strongyle could be detected. Possibly the frost of the previous night had killed them. The earth-worms were still alive and in good condition.
In conclusion, I may observe that every experimenter with helminths is well aware how unfavorable the winter season is for this kind of research. If a repetition of this inquiry in the spring or summer should confirm these results, it will prove a clear and substantial addition to our knowledge of the development of the strongyles. Meanwhile, I think that the data above given render it highly probable that the larvæ of the hoose-producing strongyle (S. micrurus) are passively transferred to the bodies of setigerous annelids, which are thus called upon to act as intermediate hosts. If this be so, it is further certain that important structural changes with ecdysis follow after their escape from the earth-worms or other annelids, moisture, dew, or water being essential to the penultimate stage of growth. Final passive transference, either with fresh fodder from swampy grounds, or, it may be, from pond water, ultimately enables them to acquire their definite sexual form, size, and other adult characteristics.
According to Mégnin it is not the Strongylus filaria, but a hitherto unknown and totally distinct species (Strongylus minutissimus) which occasions pneumonia in Algerian sheep. In England the parasitic bronchitis affecting sheep is generally called the “lamb disease.” This is unfortunate, because many other parasites prove destructive to lambs. One of the most injurious species is Strongylus contortus, infesting the true stomach, whilst S. hypostomus, occupying the small intestines, is almost equally obnoxious to the ovine bearer. By Leuckart and others this last-named worm is retained in Dujardin’s genus Dochmius, in which genus another species occurs (D. cernuus). This worm is quite distinct, but not readily distinguishable by the naked eye alone. It occasionally occupies the upper part of the colon, as well as the lower end of the small intestine. A rarer intestinal worm in lambs is the Strongylus filicollis. Several other strongyles infest the ox (S. radiatus, S. inflatus, S. gigas), goat (S. venulosus), and stag (S. ventricosus).
As showing the extraordinary prevalence and destructiveness of entozoa in certain countries, I will adduce an instance in which my opinion was requested and given some five years since. My informant stated the case somewhat in the following manner:--On a farm in New South Wales, and lying about 200 miles to the north-west of Sydney, on the Trafalgar tributary of the Macquarie river, out of a flock of about 8000 sheep no less than 1200 have perished. In many instances post-mortem examinations were made, worms appearing in all cases to be the cause of death. There were four kinds of parasites present. The most numerous were red and white, “marked like a barber’s pole.” These occurred chiefly in the fourth stomach and commencement of the duodenum, but some were found throughout the entire length of the small intestine. A second set comprised small black worms, resembling needles, scattered only in the lumen of the intestines. The third set were tapeworms, each being several fathoms in length. The fourth set was made up of white threadworms, individually measuring two inches in length. These occupied the bronchial tubes, and were characterised by my informant as “the most deadly of all.” Without the aid of specimens I at once recognised these brief diagnostic characters as severally referring to Strongylus contortus, Dochmius hypostomus, Tænia expansa, and Strongylus filaria.
What the inquirer desired at my hands was “full information respecting the general principles to be carried out in view of the prevention of this parasitic disease, regard being had to the difficulty of finding any food but pasture, to the number of animals to be treated, and to the not unfavorable circumstance that the run is divided by fencing to a great extent.” I was also requested to explain the best modes of treatment, being at the same time informed that turpentine drenchings had already been employed with only “partially effective” results. I was also expected to give numerous and varied formulæ, to be tried in succession, supposing the first should fail. Of course, it should have been known that I neither prescribe medicines nor accept fees in respect of animal patients; but, as in this instance my opinion was permitted to assume the form of a “written scientific report,” I was pleased to have an opportunity of commenting freely and fully on the significance of the facts submitted. My advice took the form of a long report, which might here be usefully given in extenso were it not somewhat of the nature of a private and privileged communication. I have no doubt that the stockowner would be pleased that I should utilise his remarkable “case” for the benefit of agriculturists and others; but it is for him to publish the “opinion” as it stands, should he think fit to do so.
Practical men, on reading the few foregoing particulars, will perceive that one of the principal obstacles to success in cases of this kind lies in the circumstance that artificial food can only be procured with difficulty. Where the source of the disease is associated with the pasture-supply, any treatment, however effectual for a time, can only be followed by partially satisfactory results.
The destructive powers of any one of the above-mentioned parasites being sufficient to produce a fatal lamb-disease, it is clear that when two or more of these particular species attack their victim in considerable numbers, the ovine-bearer has little chance of recovery. The intestinal strongyles, by means of their oral armature, behaving as veritable leeches, will, if not expelled in good time, produce a rapidly fatal anæmia, precisely in the same way as the human Anchylostomum of the tropics.
The worst of dealing with this sheep-parasite is that it will not succumb to ordinary doses of salines like the stomach strongyle; moreover, the little leech-like wounds will probably bleed after the parasites have been compelled to abandon their hold. Prevention is better than cure. Accordingly, I sought to explain the origin of these creatures, and in what possible ways the germs of the various species could be destroyed, or at least limited in numbers.
As to the drugs and inhalations to be employed, it would be difficult to advise any more effective than those commonly in vogue, the great thing being to effect changes of pasture and ground, to look to the purity of the water-supply, and to supply the best kinds of nourishment after active treatment. The diseased animals should, from the very first, be separated from their companions, because the amount of germ distribution is thereby greatly lessened. They should be at once drenched or treated by inhalation (as the parasitic nature of the attack requires), and the enclosure in which the animals have been temporarily housed should be thoroughly scoured with boiling-hot water impregnated with salt.
The nomenclature of the parasitic diseases of animals is excessively vague. Thus, apropos to the case above recorded, I may mention that an American veterinary practitioner appeared to be much shocked that I should have had the temerity to speak of four distinct kinds of lamb-disease. It is in this way that practical men often commit serious mistakes by rolling together disorders that are totally distinct. If it were true that epizoöty in lambs is exclusively due to Strongylus filaria, then professionals might aptly speak of the parasitic bronchitis of young sheep as lamb-disease; but we now know that several other helminths prove terribly fatal to lambs, occasioning death in totally different ways. In one set of cases the animals are asphyxiated; in another set they become fatally anæmic; and in a third set they perish from the severity of nervous reflex irritations. Lastly, it may be remarked that, in view of the successful management of the parasitic disorders of animals, the veterinary practitioner must necessarily be guided by the same general principles as the physician. For myself, I may say that I have hitherto designedly withheld many practical hints which a long experience with human patients suggested, not wishing to appear to dictate to those who are constantly seeing animals. However, since (contrary to my own wishes) it has happened that both professional men and agriculturists have not only invited me to give opinions, but have, at various times, asked me to prescribe, it seems there can have been no impropriety in publishing my views on this subject. Certainly I have had no professional motives to serve.
Of the few non-strongyloid nematodes, one of the commonest is Trichocephalus affinis. I have obtained this worm from the giraffe, and the parasite may be said to infest all ruminating animals, not excluding even the camels and llamas. As before remarked, the whipworm has been known to produce severe symptoms in man, and it occasions “scour” in the sheep. The eyes of cattle are occasionally infested by Filaria lacrymalis and F. papillosa. The last named is the common eye-worm of the horse. On Feb. 27th, 1875, Dr Edward L. Moss, of H.M.S. “Alert,” brought me three examples of a nematode which I referred to Filaria terebra. Dr Moss obtained these parasites in 1874, during the time that he had charge of the Naval Hospital at Esquimalt, Vancouver’s Island. They occupied the abdominal cavity of the black-tailed deer (Cervus columbianus). The worms were mostly found lying amongst the coils of the small intestine. They were not attached to the peritoneal membrane. Dr Moss had shot seventeen deer in all, the males and females being in about equal proportion; nevertheless, not one of the bucks showed any trace of the presence of these entozoa. This absence of parasites in the male deer is noteworthy. Hitherto the worm appears to have been observed in the red deer (C. elaphus), and by Natterer in three species of American roe (C. rufus, C. simplicicornis, and C. nambi). Two of the worms measured each about 2-1/3″ in length, the third exceeding 3″. They displayed in profile two prominent oral papillæ. Probably there were four of these processes, such as Dujardin described in his Filaria cervina, which, according to Diesing, is a synonym. They all possessed spirally twisted tails.
Amongst the arachnidan parasites of ruminants having entozoal habits are Pentastoma denticulatum and P. constrictum. The former larval worm is excessively common in cattle, sheep, deer, and antelopes. According to Rhind, the adult worm (P. tænioides) also infests the sheep. The P. constrictum has hitherto only been found in the giraffe. On the 10th February, 1859, I obtained numerous examples (P. denticulatum) from a bubale (Antilope bubalis) which died at the Zoological Society’s Gardens. The greater number occupied the surface of the lungs and intestines; some few, however, were enclosed in cysts beneath the pleura. In the spring of 1860 I also procured several specimens from the abdomen of a cape guevi (Cephalopus pygmæus).
The ectozoa of ruminants have received much attention, but I can merely indicate the known forms. Following Mégnin’s classification we have three well-marked varieties of the acarine genus Sarcoptes (S. scabiei, var. ovis, var. capræ, and var. cameli), two varieties of Psoroptes (P. longirostris, var. bovis and ovis), and Chorioptes spathiferus. This last is the true mange mite of the ox (or Symbiotes bovis of Gerlach). A variety of the follicle mite infests the sheep (Demodex folliculorum, var. ovis). Numerous species of tick (Ixodidæ) have been more or less fully described. Of these we have the Carapartos of the Portuguese (Ixodes bovis), attacking cattle; the I. reduvius, attacking sheep; the I. plumbeus, said to attack lambs; the I. albipictus and I. unipictus, found on the moose-deer. Probably this species also attacks cattle. A most horrible arachnidan is found on camels. I allude to Galeodes araneoides belonging to the Solpugidæ. This parasite will bite severely any person who attempts to dislodge it from the bearer. Turning to the insects, we find ruminants liable to be annoyed alike by flies (Diptera), fleas (Aphaniptera), and lice (Hemiptera). Various species of four different families of flies are apt to prove troublesome. Of the Œstridæ, attacking the ox, we have Hypoderma bovis, whose larvæ form tumours or warbles on the back; also H. lineata, Dermatobia noxialis, and Cephenomyia bovis (mihi). The larvæ of the latter reside at the root of the tongue and adjacent parts. In the sheep we have Œstrus ovis, Œ. purpureus, and Hypoderma lineata. Various species also attack goats and antelopes. Dr Kirk presented me with specimens of Œstrus from the frontal sinuses of a harte-beest or caama, and they have also been obtained from the sassabe, the saiga or colus, from the gnoo, and from the brindled gnoo, kokoon or gorgon. Mr Charles Danford presented me with several bots from an ibex. One or more species of Hypoderma have likewise been removed from the gazelle and other antelopes. The deer tribe are much attacked by bots. In the red deer we have Hyp. actæon and H. diana, a species also infesting the elk. The throat-grubs are Ceph. rufibarbis and Pharyngomyia picta; another species, also occurring in the fallow deer, Ceph. ulrichii, infests the elk, and C. stimulator the roe, the last-named deer being also infested by Hyp. diana. A throat-fly infests the reindeer, which is also frequently attacked by Hyp. tarandi. Specimens of the latter worm have been obtained by Dr Murie at the Zoological Gardens. The Hunterian Museum also contains these and other species of bots, presented by myself in Mr Andrew Murray’s name. A subcutaneous bot has been found in the musk-deer. A throat-bot (C. maculata) infests the dromedary.
In regard to the so-called free dipterous parasites and other noxious insects that attack ruminants, their name is legion. One of the worst is the tsetse (Glossina morsitans), immortalised by Livingstone. Of the Muscidæ we have the ox-fly (Musca bovina), the sheep-fly (M. cæsar), and the executioner (M. carnifex). Of the Tabanidæ we have T. bovinus and T. autumnalis, Chrysops cæcutiens, and the allied Asilus crabroniformis (Asilidæ). Amongst the specially noxious insects must also be placed Stomoxys calcitrans and Rhagio columbaschensis. This fly proves fearfully destructive to cattle in Hungary and Servia. Lastly, I can only further mention the common Melophagus ovinus. This is nothing more than a gigantic louse, which from long use agriculturists and veterinarians persist in calling the sheep-tick. It belongs to the Hippoboscidæ, the members of which family only attack quadrupeds and birds. As regards the lice (Anoplura), I have to mention Hæmatopinus vituli of the calf, H. eurysternus of cattle, and H. stenopsis of the goat; also Trichodectes scalaris, T. sphærocephalus, and T. capræ. These infest the ox, sheep, and goat, respectively.
For some account of the protozoal parasites (Psorospermiæ, &c.) infesting the flesh of ruminants I must refer the reader to Book I, Section IV, Part VI of this treatise.
BIBLIOGRAPHY (No. 49).--(Anonymous), “On the Hydatid in the Brain of Sheep,” from ‘Journ. de Méd. Vét.,’ in ‘Veterinarian,’ vol. xxviii, p. 461, 1855.--(Idem), “Note on the ‘Rot in Sheep,’” ‘Veterinarian,’ vol. xxxvi, p. 100, 1863.--(Idem), “On the Hydatid, or Tumour of the Brain (of Sheep),” under sig. of “Ben Ledi,” in ‘Veterinarian,’ vol. xii, p. 467, 1839.--(Idem), “Note on Rot in Sheep, Cattle, and Hares,” from the ‘Bristol Mirror and Scotsman,’ in ‘Veterinarian,’ vol. xxxvi, pp. 156-7, 1863.--(Idem), “Tapeworm Epizoöty in Nottinghamshire,” ‘Brit. Med. Journ.,’ 1858.--(Idem), “Prevalence of Rot in Sheep,” from ‘Carlisle Journ.,’ in ‘Edin. Vet. Rev.,’ 1863.--Baillet, “Filariæ in the Eye of an Ox,” from ‘Journ. des Vét. du Midi,’ in ‘Veterinarian,’ vol. xxxi, p. 703, 1858.--Barnett, J., “Hydatids in the Liver of a Cow,” &c., ‘Veterinarian,’ 1865, p. 236.--Beale, L. S., “On Entozoa (?) in the Muscles of Animals destroyed by the Cattle Plague,” ‘Med. Times and Gaz.,’ Jan. 20, 1866, p. 57; see also “Annotation,” ‘Lancet,’ Jan. 13, 1866, p. 45, and ‘The Microscope in Medicine,’ 4th edit., 1878.--Beneden (see Van Beneden).--Böllinger, O., “Echinococcus multilocularis in der Leber des Rindes,” ‘Deutsch. Zeitschr. f. Thier med.,’ ii, 1876, s. 109.--Brauer (see Bibl. No. 50).--Bugnion, E., “Sur la pneumonie vermineuse des animaux domestiques,” ‘Compt. Rend. de la réunion de la Soc. Helvet.,’ Andermatt, 1875.--Chaignaud, “Worms in the Eyes of Oxen (with remarks by Desmarets),” from the French, in ‘Veterinarian,’ vol. i, p. 77, 1828.--Cobbold, “Descr. of a new Trematode from the Giraffe,” ‘Rep. of Glasgow Meeting of Brit. Assoc.,’ 1854, and in ‘Edin. New. Philosoph. Journ.,’ 1855.--Idem, “On Flukes,” ‘Intellectual Observer,’ Feb., 1862.--Idem, “The common Liver Entozoon of Cattle,” ibid., March, 1862.--Idem, “The Whipworm of Ruminants,” ibid., Dec., 1863.--Idem, “Parasite-larvæ,” ibid., March, 1863.--Idem, “On the Measles of Cattle and Sheep” (see various papers quoted in Book I, Bibl. No. 13).--Idem, “On the Cattle-Plague Bodies (spurious Entozoa),” see Bibl. No. 41.--Idem, “On the Fluke Parasites of our Food-producing Ruminants,” Lect. iv of the Cantor series, pub. in ‘Journ. Soc. Arts,’ 1871.--Idem, “Remarks (&c.) in ref. to the Management of Sheep suffering from Nematoid Worms,” ‘Veterinarian,’ Oct., 1876.--Idem, “Record of preliminary Experiments with the Eggs and Embryos of the Husk-producing Strongyle of the Calf,” ibid., Dec., 1875.--Idem, in ‘Entozoa,’ pp. 145-183; also in ‘Manual,’ and in the chap. on “Parasitic Diseases” contributed to ‘Williams’ Principles of Vet. Med.’--Idem, “Remarks on Prof. Perroncito’s Researches,” ‘Veterinarian,’ Dec., 1877.--Idem, ‘Amphistomes of the Ox,’ see Bibl. No. 51.--Cooper, J., “Three Cases of Cœnurus in Calves,” ‘Veterinarian,’ 1865, p. 357.--Copeman, A., “Hydatids in the Brain of Lambs,” ‘Vet. Record,’ vol. iii, p. 337, 1847.--Cox, W., “Tænia in Lambs,” ‘Veterinarian,’ vol. xxviii, p. 446, 1855.--Creplin, fig. of Amphist. crumeniferum, in ‘Wiegmann’s Archiv,’ 1847, tab. ii, s. 30.--Crisp, E., “On the ‘Lamb-disease,’ of which Parasites in the Lungs are generally the Cause or Consequence,” repr. from ‘Journ. of Bath and West of England Soc.,’ in July to October Nos. of ‘Edin. Vet. Rev.,’ 1863.--Idem, “Note on Str. filaria,” ‘Proc. Zool. Soc.,’ 1856.--Danford (see Cobbold, Bibl. No. 52).--De Reck, “On the Draconcule (Strong. filaria aut veinulosus?) of Lambs,” from ‘Ann. de Logelin,’ in ‘Veterinarian,’ vol. v, p. 521, 1832.--Dupleune, “Hydatids in the Brain of an Heifer,” from ‘Mém. de la Soc. Vét. du Calvados,’ in ‘Veterinarian,’ vol. ix, p. 115, 1836.--Dupuy, “An Hydatid in the Lumbar portion of the Spinal Marrow of a Lamb, aged eighteen months,” from ‘Journ. Théorique et Prat.,’ in ‘Veterinarian,’ vol. iv, p. 285, 1831.--Engelmeyer, ‘Thierärztliche Wochenschrift,’ 1850, p. 191.--Findeisen, “Ech. in der Lunge,” ‘Repert. f. Thierheilkund,’ 1875, s. 48.--Fry, J., “Worms in the Trachea (of cattle),” ‘The Hippiatrist,’ vol. iii, p. 5, 1830.--Furstenberg, “On Pent. tænioides of the Sheep,” ‘Edin. Vet. Rev.,’ 1863.--Gamgee, J., “On Parasitic Diseases,” extr. from his ‘Rep. to the Privy Council,’ ‘Edin. Vet. Rev.,’ Dec., 1863.--Idem, “On Cattle Diseases (including those produced by Entozoa),” from letters in the ‘Times’ of Oct. 22, Nov. 10 and 13, &c.; in ‘Edin. Vet. Rev.,’ Dec., 1863.--Idem, “On Diseased Meat (especially in relation to Trichina),” ‘Pop. Sci. Rev.,’ Jan., 1864.--Idem, “On Sturdy in Sheep (with figs. from Van Beneden, Leuckart, and Cobbold),” ‘Edin. Vet. Rev.,’ vol. i, p. 440, 1859.--Idem, “Gleanings from the Researches of Eschricht, Haubner, A. Thomson, &c., respecting the Origin and Development of the Entozoa,” ‘Veterinarian,’ 1855.--Giacomini (see Bibl. No. 13).--Gulliver, “On the Structure of the Entozoa belonging to the genus Cysticercus,” ‘Med.-Chir. Trans.,’ ‘Lond. Med. Gaz.,’ and ‘Lancet,’ 1840-41.--Idem, “Notes on the Ova of Dist. hepaticum, and on certain Corpuscles obtained from the genus Cysticercus,” ‘Proc. Zool. Soc.,’ March, 1840, and in ‘Ann. Nat. Hist.,’ vol. vi, 1841; also ‘Month. Journ. Med. Sci.,’ vol. ii, 1842, and ‘Micros. Journ. and Struct. Rec.,’ p. 95, 1842.--Hewlett (see Bibl. No. 13).--Holmes, J., “Filaria in the Bronchi of a Calf,” ‘Vet. Rec.,’ vol. i, p. 125, 1845.--Hunter, J., “Ileum of a Ruminant containing Acephalocyst Hydatids;” see description of preparation No. 863 in the ‘Catalogue of Mus. Roy. Coll. Surg. Lond.’ (“Pathology,” vol. ii, p. 201), 1847.--Idem, “Hydatid in the Humerus of an Ox” (ibid., prep. No. 864).--Idem, “On Hydatids of the Sheep,” in supp. to his paper on ‘Human Hydatids,’ in ‘Trans. of Soc. for the Improvement, &c.,’ vol. i, 1793, p. 34.--Huxley, “On the Anatomy and Development of Echinococcus (from a Zebra),” ‘Proc. Zool. Soc.,’ and ‘Ann. Nat. Hist.,’ 1852.--Karkeek, W. F., “Notes on the Rot (or iles of the Cornish graziers),” ‘Veterinarian,’ vol. iv, p. 573, 1831.--King, E., “On the Propagation of Rot (by means of the eggs of Fasc. hepatica) in Sheep,” ‘Veterinarian,’ vol. ix, p. 95, 1836.--Krabbe, “Husdyrenes Indvoldsorme,” ‘Tidsskrift for Vet.’ (See also my notice of the memoir in ‘Lond. Med. Rec.’ for 1872; repr. in ‘Veterinarian,’ May, 1873.)--Küchenmeister (see Bibl. No. 13).--Leaver, T., “Cases of the Husk (from worms) in Cattle,” ‘Veterinarian,’ vol. ii, p. 355, 1829.--Lepper, “Hydatids in the Kidney of a Lamb (with remarks by Prof. Varnell),” ‘Veterinarian,’ vol. xxxvi, p. 524, 1863.--Lewis (see Bibl. No. 13).--Lord, J., “On some of the Parasites principally affecting Ruminants,” ‘Trans. Vet. Med. Assoc.,’ 1842-43.--Masse (see Bibl. No. 13).--Mayer, T., “On Hoose in Cattle (from Filaria),” ‘Veterinarian,’ vol. xiii, p. 227, 1840.--M’Call, J., “On Sturdy in Sheep,” ibid., vol. xxx, p. 267, 1857.--Mégnin, P., “Le Str. minutissimus,” ‘Bullet. de la Soc. Centrale Vét.,’ in ‘Rec. de Méd. Vét.,’ July, 1878, and in ‘Ann. de Méd. Vét.,’ Oct., 1878, p. 563.--Moorcroft, “Brain Hydatids,” ‘Med. Facts and Observ.,’ 1792.--Morton, W. J. T., “On the Entozoa affecting Domesticated Animals, and particularly on Fasc. hepatica or Liver Fluke in Sheep,” ‘Veterinarian,’ vol. xii, p. 735, 1839.--Mosler (see Bibl. No. 13).--Murie, J., “On the occurrence of Œstrus tarandi in a Reindeer in the Zoological Society’s Gardens,” ‘P. Z. S.,’ 1866, with woodcuts.--Idem, “On a Leech (Trocheta) found in the Viscera of a Molluscan Deer (Cervus moluccensis, Müller),” ibid., 1865.--Numan, “Over den Veelkop-blaasworm der Hersenen” (this beautifully illustrated memoir, in the ‘Trans. of the Dutch Soc. of Sciences,’ supplies an elaborate bibliography of continental writings on Cœnurus cerebralis--T. S. C.), ‘Œrste Kl. Verh.,’ 3e Reeks, 2e Deel, p. 225 et seq.--Oliver (see Bibl. No. 13).--Padley, G., ‘On Entozoa from a Sheep;’ see Sandie.--Parsons, “On Diarrhœa in Lambs (with bronchial worms),” ‘Veterinarian,’ 1855, p. 685.--Patellani, “Sturdy in Cattle,” from ‘München Jahresbericht,’ in ‘Veterinarian,’ vol. xxx, p. 81, 1857.--Pellizzari (see Bibl. No. 13).--Perroncito (see Bibl. No. 13).--Pourquier (see Bibl. No. 13).--Ralph, T. S., “On the Parasitic Nature of Pleuro-pneumonia,” &c., two papers in ‘Austr. Med. Journ.,’ 1865.--Ranke, “Pulmonary Entozoic Disease of Sheep,” ‘Path. Soc. Trans.,’ 1858; see also ‘Veterinarian,’ vol. xxx, p. 708, 1857.--Raynaud, “A Word on the Cachexia, or Rot in Ruminants,” trans. from the ‘Journ. des Vét.,’ by W. Ernes, in ‘Veterinarian,’ vol. xxxiii, p. 488, 1859.--Read, R., “Destruction of Strongylus and Filaria in the Bronchial Passages of Calves, through nasal inhalation of ether, chloroform, oil of turpentine, or rectified oil of amber,” ‘Veterinarian,’ vol. xxi, p. 604, 1848.--Reck (see De Reck).--Reed, R., “Congenital Hydatids in a Lamb,” ‘Veterinarian,’ vol. viii, p. 551, 1835.--Rhind, “Description of a species of Worm (Pentastoma) found in the Frontal Sinus of a Sheep,” ‘Farrier and Naturalist,’ vol. iii, p. 277, 1830, and ‘Lancet,’ 1829.--Robertson, “Remarks on Tænia in Lambs,” ‘Rep. of Scottish Med. Vet. Soc.,’ in ‘Veterinarian,’ 1875, p. 80.--Rochard (see Bibl. No. 13).--Rose, C. B., “On Cœnurus and Acephalocysts,” ‘Lond. Med. Gaz.,’ vol. xxiv, p. 525, 1844.--Idem, “On the Anat. and Physiol. of the Cysticercus tenuicollis,” ‘Roy. Med.-Chir. Soc. Trans.,’ and ‘Lancet,’ 1848.--Idem, “On the Vesicular Entozoa, and particularly Hydatids,” ‘Lond. Med. Gaz.,’ vol. xiii, p. 204, 1833-34.--Sandie (with Padley), “On Entozoa in the Lungs of a Sheep,” ‘Ann. Nat. Hist.,’ 1849.--Schwarzmeier, “Die Trepanation des Rindes bei Cœnurus,” ‘Wochenschr. f. Thierheilk.,’ 1875, s. 295.--Shenton, “Worms from the Stomach of a Cow,” ‘Veterinarian,’ 1844, p. 487.--Siedamagrotzky, “Hydatids in the Liver of a Cow,” ‘Bericht üb. das Veterinawesen im Kön. Sachsen,’ 1875, s. 29.--Simonds, J. B., “Death of Sheep from Worms in the Stomach (abomasum), being remarks on Mr. Haywood’s case,” ‘Veterinarian,’ vol. xxxiv, p. 525, 1861.--Idem, ‘The Rot in Sheep, its nature, cause, treatment, and prevention,’ London, 1862.--Idem, “On Filariæ in the Bronchi of Calves,” ‘Trans. Vet. Med. Assoc.,’ 1843, p. 517.--Idem, “On Strongylus in the Bladder and Intestines,” ibid., 1843.--Idem, “On Hydatids of the Liver of a Sheep (Mr Scruby’s case),” ibid., p. 331.--Idem, “On Disease of the Mesenteric Artery from Strongyli within the Vessel,” ‘Path. Soc. Trans.,’ 1854.--Idem, “Lecture on the Nature and Causes of the Disease known as Rot in Sheep,” vol. xxxiv, p. 274, 1861.--Spence, G. W., “On Œstrus of the Ox,” ‘Edin. Med. Journ.,’ 1858, and ‘Edin. Vet. Rev.,’ vol. i, p. 400.--St Cyr (see Bibl. No. 13).--Stoddart, J., “Case of Hydatids in the Liver (of a Cow),” ‘Veterinarian,’ vol. xi, p. 637, 1838.--Sutton (Lecture), ‘Gardiner’s Chronicle,’ June 29, 1872.--Sylvester, F. R., “Cases of Parasites infesting the Brains and Intestines of Lambs,” ‘Vet. Rec.,’ vol. ii, p. 40, 1846.--Thudichum (see Bibl. No. 13).--Idem, “Echinococci from the Sheep’s Lungs,” ‘Rep. Med. Soc. Lond.,’ in ‘Assoc. Med. Journ.,’ 1856, p. 195.--Tommasi (see Bibl. No. 13).--Van Beneden, “On the Development of Cœnurus,” from ‘Comp. Rend.,’ in ‘Ann. Nat. Hist.,’ vol. xiv, 1854.--Watson, K. W., “Experiment for the Cure of the gidd (Cœnurus) in a Sheep,” ‘Lond. Med. Repos.,’ 1815.--Willemoes-Suhm, in ‘Sieb. and Köll. Zeitschr.,’ Bd. xxv, s. 176.--Wilson, E., “On the Anatomy of Trichocephalus affinis,” ‘Vet. Rec.,’ 1846.--Wymann, “Note on Filaria in the Bronchi of a Sheep,” see Anon. on “Entozoa and Parasites,” in ‘Amer. Journ. Sci.,’ vol. xxxix, p. 183, 1840.--Youatt, “On Hydatids in the Sheep (symptoms, prevention, treatment, &c.),” ‘Veterinarian,’ vol. ii, p. 519, 1834.--Idem, “On the peculiar Bronchitis in young Cattle, accompanied by Worms in the Bronchial Passages,” part of lecture, in ‘Lancet,’ 1832.--Idem, “Hydatids in the Brain of a St Domingo Goat,” ‘Veterinarian,’ vol. ix, p. 443, 1836.--Idem, “Bronchitis from Worms (in Cattle),” ibid., vol. vi, p. 177, 1833.--Idem, “Hydatids in the Brain (in Cattle),” ibid., vol. vii.--Yvart, “Brain Hydatids,” ibid., 1828, p. 19.--Zahn, “Lungenwürmer beim Reh,” ‘Œsterr. Vierteljahrschr. f. w. Vet.,’ 1875, s. 125.--Zurn (see Bibl. No. 13).--For further references to the literature of Hydatids in Animals, see Bibliography No. 20, o, in the first half of this work.