PARASITOLOGY. 195 



segment ; when the segment is full of mature ova it 

 ruptures and the ova escape ; the segment now 

 shrinks, which gives the posterior extremity of the 

 worm an attenuated appearance. 



Life Cycle, — The ovum hatches a six-hooked em- 

 bryo, which is covered with cilia; by means of the 

 cilia it is enabled to move about in the water in 

 quest of an intermediate host, which is a fish; in the 

 fish it develops into the cystic or larval form, called 

 the plerocercoid. Man eating the fish infested with 

 the live plerocercoid develops the adult Bothrioceph- 

 alus Latus. 



Animal hifested. — Adult infests man; larva infests 

 fish. 



Farts hifested. — The adult infests the smal^ intes- 

 tines. The larval or cystic form infests the flesh of 

 fish. 



