144 



MANUAL OF ZOOLOGY 



SECT. 



a Sea-gull its final host ; a Cysticercus which occurs in the 

 liver of Rats and Mice is received into the enteric canal of 

 the Cat. In this way the Cysticercus or Cysticercoid is set 

 free in the enteric canal of the final host ; the Tape-worm 

 head becomes attached by means of its hooks and suckers 

 to the wall of the intestine ; and the long segmented body of 

 the Tape-worm is developed behind. 



The commonest human Cestode parasites among European 

 nations are Tcenia solium and T. saginata. The Cysti- 

 cercus stage of the former occurs chiefly in the flesh of the 



FIG. 72. Cyst of Taenia echinococcus with the developing daughter-cysts and 

 scolices. (After Leuckart.) 



Pig ; that of the latter in the flesh of the Ox ; and the relative 

 prevalence of these two Tape-worms in different countries 

 varies with the habits of the people with regard to flesh- 

 eating : where more swine's flesh is eaten in an imperfectly 

 cooked state Tcenia solium is the more prevalent, where more 

 beef, T. saginata. 



Bothriocephalus latuS, a very large Tape-worm without 

 hooks, is a common human parasite in Eastern countries. 

 Its Cysticercus occurs in the Pike and certain other fresh- 

 water Fishes. 



