284 



DISEASES Olf THE LIVER. 



Hosts. Dog, dingo, jackal, wolf. 



Life history. Starting with the adult tapeworm (Fig. 124) in the 

 small intestine of the dog or wolf, the eggs are scattered over the ground 

 and are swallowed by the intermediate host with the fodder or water. 

 Upon arriving in the stomach the egg-shell is destroyed, and -the six- 



m 



Fig. 123. — Portion of the intestine of a 

 dog infested with the adult hydatid 

 tapeworm [T(F)ua echinococciix, 

 natural size. (After Ostertag, 189.5.) 



Fig. 125. — Hooks of adult hydatid tape- 

 worm, a, From a hydatid ; 6, three 

 weeks after feeding to a dog ; c, from 

 an adult ; d, combined figures of a — c, 

 showing the gradual changes in form. 

 X 600. (After Leuckart, 1880.) 



Fig. 124. — Adult hydatid tapeworm 

 (Tcenia echinocoecus) enlarged. 

 (After Leuckart, I8a0.) 



hooked embryo, which is thus freed, bores its way through the intestinal 

 wall, and wanders, actively or passively (that is, carried along by the 

 blood), to various organs of the liody — liver, lungs, ovaries, bones, skull, 

 etc. — where it de-^'elops first into an acephalocjist, which may develop 

 further, as shown by the accompanying illustrations. The heads which 

 are formed, upon being devoured by a dog or wolf, then develop into 

 adult tapeworms. 



