ANIMAL PARASITES I I 



The male organs consist of two testes, with their ducts, the 

 vasa deferentia, and a seminal vesicle. In some flukes there are 

 in addition a well-developed cirrus, or penis, and a cirrus -pouch; 

 these are lacking in Clonorchis. 



The testes are a pair of much-branched organs lying in the 

 posterior fourth of the body, one behind the other, and extending 

 laterally beyond the rami of the alimentary canal. How many 

 lobes has each? 



The vasa deferentia (singular, vas deferens) arise near the 

 middle of each testis and run forward to about the middle of the 

 body, where they unite and, continuing forward over the loops 

 of the uterus, open into the seminal vesicle. The wide seminal 

 vesicle curves ventrally along the right side of the ventral sucker 

 and unites with the terminal portion of the uterus to form a 

 short common genital duct opening through the genital pore 

 already noted as lying close to the median anterior margin of 

 the ventral sucker. 



The female organs consist of the ovary, the vitellaria or yolk 

 glands, the Mehlis gland, the seminal receptacle, the Laurer's 

 canal and the uterus. 



The seminal receptacle is a conspicuous, lightly staining 

 ovoid body just anterior to the first testis. It lies somewhat 

 obliquely to the longitudinal axis of the fluke, with its left end 

 the more anterior. 



The ovary is a lobed organ lying in the median line just anterior 

 to the seminal receptacle. It stains more deeply than the latter 

 but is somewhat concealed by other parts. 



The vitellaria lie exterior to the two intestinal rami and 

 extend approximately from the region of the ventral sucker to 

 that of the seminal receptacle. They are made up of numerous 

 rounded glands connected by tubules and ultimately discharging 

 through the paired vitelline ducts. These originate near the 

 posterior ends of their respective vitellaria and curve to the 

 middle line, where they are united on the dorsal side of the ovary. 

 At the point of union the common duct expands somewhat to 

 form the so-called yolk reservoir. 



The oviduct is a tube which originates from the dorsal surface 

 of the ovary and unites with the yolk reservoir. 



Laurer's canal is a sharply defined sinuous tube which originates 

 from the oviduct just before its fusion with the yolk reservoir 

 and runs posteriorly around the left end of the seminal receptacle, 



