130 



HELMINTHOZOA. 



appended numerous heads, which are individually furnished with an 

 apparatus of hooks and suckers (fig. 65, 2, a, 6), calculated to fix them 

 to the surrounding tissues. 



Fig. 65. 



1. Ccenurus cerebralis (nat. size). 2. One head magnified : a, oral circlet of hooks ; 6, suckers. 



Fig. 66. 



(340.) The Cysticerei, 

 or common hydatids, 

 agree in the main fea- 

 tures of their structure 

 with the Coenurus, but 

 are provided with only 

 one head or oral orifice 

 (fig. 66, 2). These animals 

 are found in almost all 

 the viscera of the body, 

 and not unfrequently, 

 especially in pigs, exist in 

 great numbers, not only 

 in the liver, which is 

 their most usual seat, but 

 in the cellular texture of 

 the muscles, and even in 

 the eyes themselves. The 

 human frame is not free 

 from their intrusion ; and 

 when they abound, serious 

 consequences frequently 

 result from theirprescnce. 



(341.) CESTOIDEA. The Tcenice, or tape- worms, arc among the most 



1. Cysticercus tenuicollis (nat. size). 2. Head magnified : 

 a, circlet of hooks ; b, suckers. 



