82 



ZOOLOGY. 



117. Tseniada (Gr. talma, a ribbon) or tape-worms are 

 long ribbon-shaped worms, inhabiting the intestines of 

 man and other warm-blooded animals. There are three 

 different species found in the human intestines. The 

 most common kind has been called tsenia solium, be- 

 cause it was erroneously supposed that only one such 

 worm was ever found in the intestine at the same time. 

 The head of the tape-worm is furnished with s-uckers and 

 recurved hooks, by which it attaches itself to the intes- 

 tine of its host. This head, which is in reality the true 

 animal, has no mouth nor digestive organs, its nourish- 



FIGL 35. T^NIA OR TAPE-WORM. 



a, Tsenia or tape-worm ; &, head (enlarged) with hooks and suckers ; c, hooks 

 magnified ; d, joint, showing branched ovary, generative pore, and water 

 vascular canals; e t ovum; /, cystic worm (cysticercus longicollis). 



ment being obtained by absorption. It is also destitute 

 of reproductive organs. The nervous system is said to 

 consist of one or two ganglia ; but there are doubts on 

 this point. There is a water vascular system, which 

 consists of two tubes placed along the sides of the body. 

 These vessels are connected by cross tubes at each joint. 



