72 PLATYHELMINTHES 



The Reproductive Organs. — Male: Two large bodies, the 

 testes, very definite in outline, occupy the posterior end of 

 the animal. A duct from each, the vas deferens, passes for- 

 ward, and the two unite just posterior to the point where the 

 intestine branches. By means of a median, common duct, 

 they open to the exterior through the male genital opening. 

 This is situated on the ventral surface, just below the point 

 where the intestine branches. 



Female: Some of the ducts are difficult to see, and in 

 many cases they cannot be followed, but some of the organs 

 can be found in most of the specimens. 



The ovary is a lobed organ lying a little to one side of 

 the middle of the animal, and just anterior to the testes. 

 Lying against it is the saclike ootype, into which the ovary 

 opens. From the posterior end of the ootype the long, coiled, 

 ductlike uterus passes backward to near the posterior end 

 of the animal, turns and passes forward, and finally opens at 

 a point on the ventral surface near the male opening. The 

 uterus of an adult usually contains embryos and fills the 

 body, so as to obscure the other parts. 



The vitellaria consist of numerous small, rounded masses, 

 that lie near the margins of the animal. The products of 

 these organs are emptied into the ootype through a short 

 common duct, just ventral to the ootype. Do you know what 

 they are for? Laurer's canal is a short duct which leads 

 from the ootype to the exterior. Its function is doubtful. 



Cort: North American Frog Lung Flukes. Trans. Am. Micr. Soc, 34, 



1915. 

 Goto: Studies on the Ectoparasitic Trematodes of Japan. Jour. Col. 



Sci. Imp. Univ. Tokyo, 8, 1894. 

 Linton: The Process of Egg Making in the Trematode. Biol. Bull., 



14, 1908. 

 Leuckart: Die Blasenwurmer und ihre Entwicklung. 1856. 



: Die Parasiten des Menschen. 



Schauinsland : Beitrag zur Kenntnis der Embryonalentwicklung der 



Trematoden. Jen. Zeit. f. Naturwiss. Neue Folge, 9, 1883. 

 Thomas: Development of the Liver Fluke. Quart. Jour. Mic. Sci., 23, 



1883. 



