Part 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.