1887.] 
Mr Frank E. Beddard on Earthworms. 
159 
muscular (fig. 3 m) tube, while the distal region is thick and glandular 
(fig. 3 gl) ; with the aperture is also connected a thin-walled sac con- 
taining a bundle of long penial setae. 
Spermathecoe. — In the 8th segment are a pair of oval spcrma- 
tliecee, which open on to the exterior in the groove which separates 
this segment from the one in front. As is so generally the case, 
they are provided with a diverticulum. The diverticulum of each 
spermatheca lies in the segment in front of that which contains the 
spermatheca itself, and is remarkable in being actually larger than 
the spermatheca. In most, if not in all, the genera of earthworms 
which are included in Perrier’s two groups, Intraclitellians and Post- 
clitellians, the spermathecae open close to the anterior boundary of 
the segment which contains them. In certain species of Lumbricus 
and other Anteclitellian genera, the position is sometimes different, 
the spermatliecal apertures being situated near to the posterior 
boundary of their segment. In one instance, at any rate, the 
spermathecae actually perforate the mesentery bounding the segment 
which contains them on their way to the exterior. In a species of 
earthworm lately described by myself in a note communicated to 
the Eoyal Society of Edinburgh,* this is the case with one or more 
of the seven pairs of spermathecae which are present in that species. 
It might be imagined, therefore, that in Neodrilm the anterior 
larger portion of the spermatheca really corresponds to the sper- 
matheca, while the posterior smaller portion is the homologue 
of the diverticulum so constantly found in Perichceta, Acanthodrilus , 
and in other genera. Without an examination of the minute 
structure of the two regions of the spermatheca, it would be 
difficult to say which was spermatheca and which diverticulum. 
In three species of Acanthodrilus I have described, I believe for 
the first time, a very marked difference in minute structure between 
the spermatheca and the diverticulum, which is correlated with the 
fact that the spermatozoa always appear to be stored up in the 
diverticula. In the present species I find an identical difference 
in the structure of the spermatheca and its appendage, which leads 
to the inference that the anterior sac is the diverticulum. Seeing 
that in many cases, especially in Perichceta , the diverticula of the 
spermathecae extend into the segment anterior to that which con- 
* Proc. Pioy. Soc. Edin., 1885-6, p. 451. 
