190(5.] WORMS OF THE THIRD TANGAXYIKA EXPEDITION. 211 



nearly ripe ova are not all to be found at or near the free edge 

 of that gonad. I noted cells far on the way to become ripe ova 

 at some distance in the intei-ior of the gonad, and in front of 

 these was a thick layer of germinal cells not far advanced along 

 the same road. 



The oviducts, as in Euclriloides also, open freely into the cavity 

 of the xiiith segment. This, however, is a character also shared 

 by Platydriliis. But the present genus (if it be rightly elevated 

 to distinct generic rank) does not show the connection between the 

 ovidvict and the spermathecal sac which exists in Platydi-ilvjS*. 

 The oviducal funnel is very extensive, more so than in a large 

 number of Oligochaeta. The upper lip is very long, extending 

 dorsally into actual contact with the dorsal blood-vessel as it 

 traverses the septum. The lower lip of the funnel is pushed into 

 and, as it were, tucked away into the receptaculum ovorum, which 

 lies on the opposite side of the septum in segment xiv. 



The oviduct itself, instead of running a straight course to the 

 oviducal j)oi'e in the xivth segment, pi'ojects forward into the 

 cavity of segment xiii. as a loop enclosed in a continuous muscular 

 sheath. This U -shaped region of the oviduct differs in no way in 

 structure from the rest of the tube, which runs an approximately 

 straight course. The oviduct, therefore, is like the sperm-duct of 

 certain Eudrilids (e. g., Stuhlmannia), in that it passes tln-ougli 

 the septum xiii./xiv. and, instead of opening into segment xiii. 

 and facing forwards, turns back and for the most part at least 

 faces back again into segment xiv. We have, however, to consider 

 the long tract of cubical epithelium which lies along the anterior 

 face of septum xiii./xiv., extending up to the level of the dorsal 

 vessel. That this is continuous with the actual indipping of the 

 funnel of the o^^.duct is without doubt. At the same time it 

 seems possible to compare this tract of epithelium with the egg- 

 conducting apparatus of other Eudi^ilids. It represents, as I 

 think, potentially part of the egg-conducting apparatus (the so- 

 called spermatheca) of Eudrilus f. I have lately shown that the 

 large sacs in that genus ai-e a development of the septum dividing 

 segments xiii./xiv., and that primitively the epithelium of the 

 oviducal funnel is continuous with a layer of equally cubical 

 epithelium which with the muscular wall behind it is evaginated 

 into the xivth segment to form the sac in question. In early 

 stages such as I studied it is not possible to draw a distinct line 

 between oviducal funnel and the epithelium of this sac. An 

 earlier stage still (which I did not find in Eudrilus) would be, 1 

 should imagine, a continuation of the epithelium over the septum 

 without a trace of the evagination. This state of affairs is 

 precisely what we have in the Eudrilid which forms the subject 

 of the present remarks. I do not think, however, that it is a 

 temporary stage, and that the ultimate product would be a sac oi' 

 sacs like those of Eudrilus, and for the following reasons : — 



* Here I confirm Michaelsen, who queries the fact. 



t " The Gonad of Endrihis," P. Z. S. 1902, vol. ii. p. 89. 



Proc. Zool. Soc— 1906, Vol. I. No. XV. 15 



