248 
FRANK E. BEDDAR1). 
mature ova lying in the body-cavity behind the thirteenth 
segment quite detached from the reproductive glands of that 
segment. They appeared to be contained in the fourteenth or 
fifteenth segment, or even to occupy both of these segments. 
In at any rate one instance these bodies appeared to be con- 
tained in a thin-walled muscular sac, to the walls of which 
were closely applied the transverse vascular trunks. In the 
other cases they were grouped together, but I did not. observe 
any structure resembling a muscular sac surrounding them. 
The maturation of the ova 1 of Urochseta outside the gland 
in which they are developed is of some interest, even if the 
supposed muscular sac enveloping them is nothing but a 
partially detached (by the processes of embedding, &c.) portion 
of the delicate intersegmental septa. Moreover, the ova them- 
selves differ in some important particulars from the ova of the 
majority of Earthworms. 
Vejdovsky (29), as well as the earlier observers d'Udekem 
and Claparede, dwells upon the fact that the ova of Earthworms 
are small and numerous as compared with those of the majority 
of the aquatic Oligochseta, which are large and few. The 
greater size of the ova of the “ Limicolae ” is due to the fact that 
they contain very much more abundant yolk. The greater 
development of yolk in the ova of the “ Limicolae ” is, Vejdovsky 
thinks, due to the different way in which they become mature. 
In the aquatic Oligochaeta the ova detached from the ovary 
are nourished by the perienteric fluid, while the ova of Earth- 
worms remaining in the ovary are provided with special blood- 
capillaries. The latter mode of nutrition, as the facts prove, 
leads to the formation of numerous small ova, the former to the 
1 I found these structures in two specimens of Urochseta, and occupying 
the same position. I cannot, however, be certain that they are not Gregarines. 
I am not aware that it is possible in preserved specimens to be absolutely 
certain about such a point. All that can be said is that the bodies in question 
arc closely similar to the ovarian ova of Phreoryctes, and that I only found 
them in the situation mentioned. The fact of their not being surrounded by 
smaller ovarian cells as arc the egg masses of llhynchclmis is not a 
conclusive argument, since in Earthworms the ova in the receptacnlum are not 
accompanied by sucli cells. 
