TAPE-WORMS. 



93 



is very common in warm countries. ASCA'RIDES, which are found 

 in the intestines of man, also belong to this division. One species, 

 the lu?n' bricus, sometimes attains to fifteen inches in length. 

 11. To the second division, parenchy' mata> belongs the tape- 



i-. 82. 



Fig. 83. TJENIA TAPE-WORM. 



worm ( Tce'nid). The body is terminated anteriorly by a small 

 head (fg. 83, a), having two or four pits, and, frequently, one or 

 more proboscis-like appendages ; but the mouth is very indistinct, 

 and the digestive apparatus is generally reduced to a double 

 longitudinal vessel (jig. 82). The body is ordinarily flat, very 

 long, and divided into a great many more or less distinct joints 

 (Jig. 83). Each segment or ring has one or two pores which 



communicate with the 



longitudinal 



vessels, and contains a dis- 



Explanation of Fig. 82. A ring or segment of a tsenia, magnified, show- 

 ing the ovaries ; o, the two longitudinal vessels and the lateral pore ; ft, a 

 segment from which almost the whole ovary has been removed. 



Explanation of Fig. 83. Represents the ribbon-like body of the tape. 

 worm and the lateral vessels running through its whole length on each 

 side ; a, the head. 



11. How are tape- worms characterized? Where are they found ? 



