108 S. GOTO. 



mass at the time. I think this the more prohable, as the only specimen 

 I have examined had numerous ego-s in its uterus, in the formation of 

 which all the sperm mass that may have been present in the seminal 

 receptacle would have been used up (PI. X, fig. 1). 



In Onchocottjle spinacis the seminal receptacle is a tolerably large, 

 ellipsoidal sac situated just in front of the ovary, and is provided 

 with a long stalk, by means of which it communicates with the 

 oviduct at the point where the latter receives the unpaired yolk-duct 

 and the genito-intestinal canal (PL XV, figs. 1 & 2). It therefore 

 presents some ditterence from that of Onclio. appendiculata, in which 

 it is, according to Taschenberg, merely a local enlargement of the 

 oviduct. 



Close to the ovary the wall of the oviduct consists of a thin 

 structureless membrane ; but as we approach the ootyp there is a thin 

 layer of homogeneous or very finely granular substance probably of a 

 protoplasmic nature, which stains pretty well with haematoxylin, 

 so that the membrane just referred to above is in reality a true base- 

 ment membrane with probably a very thin protoplasmic layer on its 

 inner surface. I have nowhere been able to observe any nucleus in 

 the wall of the oviduct ; but that it originally consisted of a true 

 epithelium seems to me beyond doubt, from the presence of tlie 

 protoplasmic layer already mentioned, and from the fact that nuclei 

 are present in other parts of the female efferent duct. In Dldidophora 

 the oviduct presents at short intervals circular thickenings of its wall 

 exactly similar to those which will be described afterwards in the 

 genito-intestinal canal. 



Ootyp — The ootyp is a spindle-shaped portion of the female 

 efferent duct situated between the oviduct and the uterus, where the 

 ovum and the yolk-cells become enclosed together in the egg-shell. 

 In many species it is always distinctly set off from the other parts of 



