282 



ZOOLOGY 



SECT. 



in certain Earthworms, another in a Myriapod (Glomcris 

 limbatus). 



Tccnia ccenurus of the Dog has a bladder-worm stage in the 

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



FIG. 223. Cyst of Tccnia ecliinococcus with the developing daughter-cysts and scolices. 



(After Leuckart.) 



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

 the best known instance of multiple production of scolices in a 

 cysticercus is Tccnia ecliinococcus well known as cause of the 

 disease termed hi/datids, 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 daughter- 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 



FIG. 224. Scolices of T. echinococcus. 



(After Cobbold.) 



FIG. 225. Separate scolex of 

 T. echinococcus. (After 



and 225), 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 



