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.

BOOK 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.

Part 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.

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.

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.

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.

PART 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.