58 HELMINTHOLOGY 



c. Sexual organs, just back of the neck-like portion, in the 

 region of the ventral sucker, notice the coiled uterus, yellowish 

 in color, and filled with eggs. The yolk reservoir may be located 

 just back of the uterus in the median line, as a dark colored more 

 or less triangular organ, two ducts leading to it from the sides; 

 these ducts in turn lead off to the finely branched yolk glands, 

 seen as tiny dark spots on both sides of the body. The ovary is 

 a definitely branched body lying to one side in front of the yolk 

 reservoir. The ovary can be easily distinguished from the 

 similarly branched testes, which are paired, by the fact that the 

 latter occupy the greater part of the central area of the fluke. 

 The ovary is usually darker and more compact. The penis 

 and the genital pore are located within the area of the ventral 

 sucker. 



d. Digestive system. This consists of the mouth, located 

 within the oral sucker, leading to a prominent pharynx, in turn 

 leading to the bifurcated intestine, which lies along the lateral 

 margins of the body, is much branched, and ends blindly. 



e. Excretory system. The excretory system may be distin- 

 guished as a median light canal extending forward from the 

 posterior end of the body. 



Draw the specimen, indicating and labelling the parts seen. 

 F. Examine a portion of an infested liver, and notice the 

 characteristic lesions produced by the fluke. 



EXERCISE 32 



OTHER TREMATODES 



A. Dicroccdium (Distomum) lanceolatum is the lancet fluke 

 of sheep and cattle. Examine several specimens of this species. 



a. How does it differ in size from Fasciola hepatica? . b 



b. Does the form of the fluke justify the specific name? 

 Describe its form. 



