282 



ZOOLOGY 



in certain Earthworms, another in a Myriapod (Glomcris 

 Jiinhaius). 



Tcrnia ecunurus of the Dog has a bladder-worm stage in the 

 Sheep and Rabbit whicli gives rise to several tape-worm heads, 



Fiii. 223.— Cyst of Tasnia ecllinococcus with the developing daughter-cysts and scolices, 



(After Lcuckart.) 



and the same holds good of Tcrnia serialis from the Fox. But 

 the best known instance of multiple production of scolices in a 

 cysticercus is Tamia echinococcus — well known as cause of the 

 disease termed hydatids, common in Man and in various domestic 

 animals. In this case the hooked embryo develops into a large 



mother-cyst, from the interior 

 of which daioghter-cysts are 

 budded off (Fig. 223). Event- 

 ually from the walls of these 

 daughter-cysts there are 

 formed numerous tape-worm 

 heads, or scolices (Figs. 224 



Fii;. 224.— Scolices of T. ecbinococcus. 



(After Cobljold.) 



Fi<;. 22.5. — Separate seolcx of 

 T. echinococcu&. (After 

 Cohbold.) 



and 22.5), which, when fully formed, assume the appearance of 

 cysticercoids without the caudal vesicle. These are readily de- 

 tached, and, should the organ in which the cyst has been 

 developed be devoured by a Dog — which is the final host of the 

 parasite — some of these scolices become attached to the wall 



