238 



S. YOSHIDA : 



The testes are three in number to each segment (figs. 8 & 9, t). 

 They are spherical, generally measuring 0.03-0.04 mm. in diameter, 

 and are arranged In a transverse row on the dorsal side of cirrus pouch. 

 In the immature state they are represented by compact nucleated 

 spheres (fig. 9, /) ; when fully mature, they assume a granular and 

 fibrous appearance due to the development of spermatozoa. 



Female reproductive organs. — The ovary is a transversely elongate 

 sac-like organ, situated postero-ventrally in the segment (figs. 5 & 

 8, ov.). 



The yolk-gland is a distinct cell-mass, situated ventrally in the 

 median line (figs. 5 & 8, yg.). 



The vagina pursues a straight course mediad along the ventral 

 side of cirrus pouch, crossing the excretory vessels of the porose 

 side on the dorsal side. It is thickest (0.007-0.01 mm. thick) in the 

 distal parts. In mature segments it is a very thin-walled tube. 

 Proximally the caliber gradually decreases. The proximal end makes 

 a few windings before it opens into the seminal receptacle (fig. 8, vg). 



The seminal receptacle, situated mainly in the median line between 

 cirrus pouch and yolk-gland, is an ovoid body, measuring 0.04-0.05 

 mm. by 0.025-0.03 mm. (fig. 8, sr). 



The uterus is sac-like, lying transversely antetior to ovary (fig. 

 IO, ut). In the posterior segments it is greatly distended and occupies 

 all the available spaces in the segment, being filled up with eggs in 

 advanced stage of embryological development. The uterine wall is a 

 thin membrane consisting of flattened cells with distinct nucleus. 



Mtisadatiire. — There is only one longitudinal muscle layer, corres- 

 ponding to the outer longitudinal muscle layer of certain other 

 Hymcnolepis species. That layer consists of about one hundred or 

 more muscular bundles regularly arranged in a row along the entire 

 body margin (fig. 8, Im). Each bundle is thin, being only 0.0025 nim - 

 in diameter. 



Excretory canals. — As usual there are seen two main excretory 



