OESTODA 



113 



The first successful rearing of Tanice 

 with human hydatids was accomplished by 

 Naunyn (1864), his results being subse- 

 quently verified by Krabbe and Finsen 

 (1865). Zenker, Ercolani, and several 

 others, including myself, also conducted 

 feeding experiments with human hydatids 

 which were attended with negative re- 

 sults. In the case of one of my experi- 

 mental dogs the animal was liberated by 

 an ill-disposed person before I had oppor- 

 tunity to destroy it. As the experiment 

 was carefully conducted, the animal may 

 have proved a source of fresh echino- 

 coccus-infection. Mr E. Nettleship's emi- 

 nently successful experiment was made 

 with hydatids obtained from a sheep. 

 The converse experiment, namely, that of 

 rearing hydatids with the mature pro- 

 glottides of Tcenia echinococcus adminis- 

 tered to animals, has been performed most 

 successfully by Leuckart, and by Krabbe 

 and Finsen ; by the former in the pig, by 

 the latter in a lamb, with tapeworms 

 that had also been reared by experiment. 

 Zenker, later on, reared the Tania from 

 hydatids obtained from an ox. 



The sexually mature T&nia echinococcus 

 may, for the purposes of diagnosis, be 

 characterised as a remarkably small ces- 

 tode, seldom reaching the fourth of an 

 inch in length and developing only four 

 segments, including that of the head ; 

 cephalic extremity capped by a pointed 

 rostellum, armed with a double crown of 

 comparatively large-rooted hooks, from 

 thirty to forty in number; the four 

 suckers prominent, and succeeded by an 

 elongation of the segment forming the 

 so-called neck ; final segment, when sexu- 

 ally mature, equalling in length the three 

 anterior ones 



. ., FIG. 29. Tania echinococcus Stro- 

 at the bile. Mag. 30 diam. Original. 



