190 



PRACTICAL ZOOLOGY 



tened to the wall 

 of the intestine, 

 and a series of 

 proglottides is de- 

 veloped. 



The adult tape- 

 worms found in 

 the alimentary 

 canal of man and 

 other animals in- 

 terfere seriously 

 with the digestion 

 and absorption of 



food, but the larvae are more dangerous. For example, the larva; 



of the tapeworm, Tama echinococcus (Fig. 112, A), which lives 



Fig. hi. — Stages in the development of a tapeworm. 



a, egg with embryo ; b, free embryo ; c, rudiment 

 of the head as a hollow papilla on wall of vesicle ; d, 

 bladder-worm (cysticercus) with retracted head; e, the 

 same with protruded head. (From Sedgwick.) 



Fig. 112. — A, an adult hydatid tapeworm. 



B, brain of a lamb infested with young gid bladder worms. 



C, diagram of part of an hydatid. (After Blanchard.) 



