TJENIA. 



287 



fine and granular and the outer envelope thin and smooth. 

 There is nearly always a flattening on the side of one of the 

 poles, which breaks the symmetry of the ovoid and is a dis- 

 tinguishing characteristic of the ova. Infection takes place as 

 with the ascaris. 



The Trichocephalus dispar, or Trichocephalus trichyuris, the 

 very common whip worm, is considered to be of no great 

 pathological significance. Its ova are very often found in the 

 faeces, and resemble waiters with handles at each end. The 

 ova are about the length of the oxytiris, but somewhat nar- 

 rower. They are brown in color, with a double contoured 

 thick envelope and the protoplasm is coarser. The "knobs 77 

 on the ends mark them effectively from confusion with other ova. 



T-ENIA. 



Of the tienia, or tapeworms, there are three principal vari- 

 eties. Common to all is the intervascular system, intercom- 

 municating between segments (proglottides), and the her- 



FIG. 84. 



Tsenia saginata: Head; proglottis ; egg (Reichert's eye-piece III, objective IV). 



(von Jaksch.) 



maphroditic character of the latter. The ova are very rarely 

 found in the intestines. They may be found in a mature 

 link, usually any one after the 450 from the head, by teasing 



