Chap. IX.] 



HOOKS OF CESTODA. 



2 8 7 



hooks, or of bristles. The former are well developed 

 in some of the Cestoda, as in Taenia solium (the 



Pig. 120. tierpula vermicular, showing tlie coiled Tube, and the 

 Animal protruded. 



tapeworm), where the head is surrounded by a 

 circlet of recurved chitinous hooks, by means of which 

 the animal fixes itself to the mucous membrane of the 

 intestine of its host ; the presence of these is the cause 

 of the difficulty found by the practitioner in attempting 

 to expel the parasites from the human intestine. 



