Japanese Freshwater Triclads. 



37 



aroaiul the penis-bulb are numerous eosinopliil penis-glands, 

 the duets of which entei' the penis at the base and open into the 

 ejaculatoiy duct throughout, between the expansions mentioned 

 above. 



sr 



Text fig. 11. DiagTam of genital organs of S, sappt?ro iu sagittal section. 

 Index letters as in text figs. 2, 5 and 6. 



The paired ovary is placed ventrally between the first and 

 second, sometimes between the second and third, branches of the 

 anterior gut trunk. It is a spherical mass of relatively few egg- 

 cells in several stages of development and is enclosed by a distinct 

 delicate membrane. The youngest ova are found in the foremost 

 part and the most mature ones in the central and hind parts, from 

 the postero-hiteral surface of which the oviduct starts as an 

 ampuUaceous passage. Scattered in between the ova are branch- 

 ing cells which fill the spaces between them. The cells have 

 been considered by some authorities (Moseley (54). von Kexxel 

 (45), Lang (48), Wooüwortii (98), etc.) as resulting from the. 

 differentiation of the connective tissue. However, as mentioned 

 by I.7EMA (38), von (}raff (31), Böhmig (0) and others, the}^ 

 appear to be regarded as rudimentary egg-cells, at whose expense 

 the ova develop. 



