108 



s. GOTO. 



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

 I have examined had numerous eggs in its uterus, in tlie formation of 

 ■\vhich all the sperm mass that may have been present in the seminal 

 receptacle would have been used up (PL X, ßg. 1). 



In Onchocotiile 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 cnnal (PI. XV, figs. 1 & 1^). It tlicrefore 

 presents some ditlerence from tliat o[ Onclio. aiipcndiciihila, in which 

 it is, acc( )rdi ng to T a s c h e n 1 ) e r g , merely a local enlargement of the 

 oviduct. 



Close to the ovary tlie 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 pro1)ably of a, 

 protoplasmic nature, which stiiins prett\^ well with haematoxylin, 

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

 ment membrane with probably a: very thin })roto[)Lismic layer on its 

 inner surfice. 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 doidjt, from the presence of the 

 protoplasmic layer already mentioned, and from the fict that nuclei 

 are present in other [)arts of the female efferent duct. Tn Dididnphorn, 

 the oviduct presents at short intervals circular thickenings of its wall 

 exactly similar to those which Avill be described afterwards in the 

 genito-intestinal canal. 



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

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

 ovum and the yolk-cells l)ec<3me enclosed together in the egg-shell. 

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



