Diseases of cattle, sheep, goats Diseases of cattle, sheep, goats and swine diseasesofcattl00mous Year: 1905 294 DISEASES OF THE LIVER. the biliary ducts of oxen, sheep, and goats of two species of distomata, viz., the Distoma hepaticum or Fasciola hepatica, and the Distoma lanceo- latiim. In 1875 Zimdel established the causative relation between the pre- sence of distomata in the liver and the development of progressive fatal cachexia in most of the animals affected. This opinion was emphasised by the works of Leuckart and Thomas on the development of distomata, and at the present day the
Diseases of cattle, sheep, goats Diseases of cattle, sheep, goats and swine diseasesofcattl00mous Year: 1905 294 DISEASES OF THE LIVER. the biliary ducts of oxen, sheep, and goats of two species of distomata, viz., the Distoma hepaticum or Fasciola hepatica, and the Distoma lanceo- latiim. In 1875 Zimdel established the causative relation between the pre- sence of distomata in the liver and the development of progressive fatal cachexia in most of the animals affected. This opinion was emphasised by the works of Leuckart and Thomas on the development of distomata, and at the present day the parasitic theory is accepted as beyond question. Fasciola hepatica {Distama liepatkum).—The common liver fluke of cattle, sheep, swine, etc. Life history. The adult parasite, instead of producing young similar to itself and capable of developing directly into adults in cattle, pro- duces eggs which develop into organisms totally different from the adult form, living a parasitic life in other animals. In scientific language, the parasite is subject to an alternation of genera- tions, together with a change of hosts. The fol- lowing summary of the life history will make this point clear:— {a) The adult Jienitapliroditic worm (Figs. 144 and 145) fertilises itself (although a cross fertilisation of two individuals is not impossible) in the biliary passages of the liver, and produces a large number of eggs. (b) Eggs (Fig's. 143, 146 and 147).—Each egg. is composed of the Fig. 142.—FasciolaJiepa- tica. A, 3oung; B, adult parasite. (After Railliet.)
Size: 943px × 2120px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
