Parasitic worms, with a note on a free-living nematode / by R.T. Leiper and E.L. Atkinson.

  • Leiper, Robert Thomas, 1881-1969.
Date:
1915
Catalogue details

Licence: In copyright

Credit: Parasitic worms, with a note on a free-living nematode / by R.T. Leiper and E.L. Atkinson. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    During these winter months, as soon as the hosts were killed or caught outside, their bodies or excised portions froze almost immediately. It was therefore necessary to take them hack with us to our hut and thaw them out in order to he able to examine them. In the case of larger animals, like the seals, this proved unpleasant for the other members of the party. The fishes were caught by digging a hole through the ice, and lowering a trap baited with seal-meat or seal-intestine—the latter being the better bait. The trap was made of rabbit-wire, spread over iron bars, seized to hoops of iron. At either end there was a cone-shaped entrance made of wire. By this method as many as three hundred fishes were cauidit from one hole. O The fishes were all Trematomus bernacchii.* Altogether five species of Trematodes, three of Echinorhynchi, some larval Echinorhynchi, larval Nematodes, and Cestodes, besides parasitic Crustacea and Protozoa, were obtained from these fishes. The seals were of three kinds:—Weddell's Seals, Crab-eating Seals, and Sea- Leopards. The Weddell's Seals (Leptonychotes weddelli) were for the most part older than the others and seemed more heavily infected ; they contained at least six species of Cestodes, one Trematode of special interest, two Nematodes, and one or two species of Echinorhynchi. An encysted Echinorhynchus larva is shown later to be the young of E. hamanni, which attains maturity in Weddell's Seal. Mr. D. C. Lillie collected two species of Nematodes and two of Cestodes from the Weddell's Seals caught on the Southern voyage of the Terra Nova, 1911-1912. The Trematode found in the Weddell's and Crab-eating Seals turned out to be Ogmogaster plicatus, previously described in 1829 by Dr. Creplin from the intestine of a Rorqual [Balaencptera acuto- rostrata) in the Arctic regions. In 1891 this form was again described by L A. -lager- skiold from the alimentary canal of l>. iicitforostnifa and ]>. muscidus,^ obtained on the Northern shores of Norway. The infection of the alimentary canal of the old Weddell's Seals was a truly wonderful sight. The stomach contained a mass of Nematodes. Immediately after the pyloric opening there was a bunch of large Cestodes with their heads fixed beneath the first few valvulae conniventes. The remainder of the small intestine was one felted mass of Cestodes, large and small. The Crab-eating Seal (Lobodon carcinophagus) supplied one species of larval Nematode, one species of Echinorhynchus and Ogmogaster plicatus. These seals were small ;nid immature, and were comparatively lightly infected with parasites. The Sea-Leopard [ELydrurga leptonyx) provided one species of larval Nematode and * Mr. Regan has pointed out that the fishes caught in traps at the Winter Quarters belonged to two species, Trematomus bernacchii and T. Jiansoni; as is shown by Dr. E. A. Wilson's drawings and specimens (see Vol. I, No. 1, p. 3, PI. I). The collectors of the material apparently did not dis- tinguish between these two species.—S.F.H. f The Common Rorqual.—S.F.H. F 2