368 



THE DEVELOPMENT OF CESTODES. 



at different stages of development, and all hanging together by means 

 of a thin stalk at the posterior end of the caudal bladder. Here, too, 

 of course occurs the formation of the buds, which at first are nothing 

 else than accumulations of cells, which force their way out, and are 

 surrounded by a continuation of the cuticle. It is unnecessary to 

 give any account of the metamorphosis of the buds, since to do so 

 would only be to repeat what we have already noted in the case of 

 Cysticcrcus arionis regarding the structure of the tape-worm head and 

 of the later caudal bladder ; for in this case the bud is nothing else 

 than a repetition of the six-hooked embryonic body. 



FIG. 214. Cysticercvt glomeridis (after Villot). A, Two groups of bladder-worms 

 produced by proliferation (under low power) ; , Cytticercu* in its natural position ; 

 and (7, with evaginated body. ( x 200.) 



After these observations, it cannot be doubted that the develop- 

 ment of the Tcenice follows, on the whole, the same type in the higher 

 and lower forms. With the exception of a few somewhat doubtful 

 cases, this is true throughout of the Cysticercoid state. It is true 

 that many differences occur in the size and nature of the bladder ; but 

 however remote certain species may be from each other, they are 

 always connected by intermediate forms. Consequently, the difference 

 which we formerly established between the true bladder-worms and 

 the Cysticercoids becomes a distinction of somewhat doubtful value. 



On the other hand, it must not be overlooked that the apparently 

 " dropsical " nature of the bladder in the genuine bladder- worms con- 

 stitutes a very remarkable and striking peculiarity, and all the more 



