19 



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 larvae 

 of the tapeworm, Tania echinocoecus (Fig. 112, A), which lives 



FIG. in. 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.) 



