44.0 FRANK 5. BEDDARD. 
seems to suggest that the former is developed first. The matter, 
however, requires renewed study, especially since Bergh (18) 
has pointed out thatin Lumbricus the relations of the sperma- 
theca to the epidermis are very similar, though there can be no 
doubt that the spermatheca is an invagination of the epidermis. 
In many hermaphrodite animals in which there is reciprocal 
fertilization, there are pouches connected with the oviduct or 
in its immediate neighbourhood which receive the sperm 
from another individual; this occurs, for example, among 
Mollusca and Planarians. In one genus of Earthworms, viz. 
Eudrilus (see p. 450), the spermathece open in common with 
the oviducts; it may be regarded as absolutely certain that 
the large pouches in this genus are really spermathece, since 
they contain spermatozoa ; and no one has been able to discover 
any spermathece in those other segments of the body where 
they might be expected to occur. As fully mature examples of 
Eudrilus have been studied by several observers, it does not 
seem likely that such spermathece exist. An arrangement of 
this kind might perhaps have been inherited from the Plana- 
rian form from which the Oligocheta have been derived. 
The question next to be considered is, how far do the sper- 
mathece of EKudrilus correspond to the spermathece of other 
Oligochzeta which have no such connection with the oviduct ? 
It seems perfectly clear that they do correspond to the sper- 
matheca in Teleudrilus, as I point out later in this paper. 
Perhaps also the spermatheca of such genera as Lumbri- 
culus which occupy the same segments as the oviducts may 
have the same history. But this hypothesis hardly seems to fit 
in with the structure of Acanthodrilus, where the sperma- 
thece are in segments vil and rx, and the aperture of the 
oviducts in segment xiv, and of the majority of Harthworms, 
where the spermathece and oviducts are separated by an 
equally wide interval. 
In Acanthodrilus Rose, as already mentioned, the diver- 
ticulum consists of a number of small pouches bound up in a 
common sheath and connected by a thick-walled muscular duct 
with the spermathece just at the point of opening. This duct 
