of Edinburgh , Session 1885-86. 
681 
not mere hollow cavities filled with developing spermatozoa, but, as 
Bloomfield has shown, are divided up in a reticulate fashion by 
septa of connective tissue. There are therefore some reasons for 
supposing, that in Eudrilus the female generative apparatus is similar 
to the male generative apparatus; that the structures which I have 
described as ovaries correspond to the receptaculum ovorum described 
by Hering, Horst, and recently by Bergh ( Zool . Anzeig ., Bd. ix. 
p. 232) in Lumbricics, and that, therefore, the true ovaries remain to 
be discovered. Such a similarity would be interesting, more espe- 
cially because it would be a further development of the conditions 
met with in other Lumbricidae; but I am inclined to think that it 
does not occur in this genus ; the fact that the supposed ovaries 
contain not merely mature and immature ova, but that they consist 
of numerous tubules, evidently lined with a germinal epithelium, 
from which the ova arise, and the fact that these tubules converge 
and open into the oviduct, appears to me to show that they are the 
real ovaries. 
(4) The formation of a columnar follicular epithelium surrounding 
the ova has not, to my knowledge, been observed in any earthworm. 
In the summary of observations on the ova in different groups, 
given in the first volume of Balfour’s Comparative Embryology , 
there is no statement concerning the presence of a follicular epithe- 
lium, which, however, is known to occur in Sipunculus and in the 
Leeches. In the latter group it has been described by several 
writers, including Jijima* and Schneider,! but appears to form a 
continuous protoplasmic mass investing the ovum, and containing 
nuclei. In Sipunculus and the Echinodermata, and in Lumbricidae 
there is a follicular epithelium which is formed of flattened cells. 
The follicle of Eudrilus appears, in fact, to resemble that of certain 
lower vertebrata more than any segmented worm; but in the absence 
of more extended information than we possess at present, I do not 
wish to be understood to insist upon this similarity. 
The ovum, with its surrounding follicular epithelium, is displayed 
in fig. 5 ; the cells, as will be seen from that figure, are very small, 
and I was unable to detect a nucleus. The appearances illustrated 
* See Isaa Jijima, “Egg Strings, &c., of Nephelis,” Quart. Jour. Micr. Sci., 
vol. xxii. (new series), p. 159. 
t Das Ei und seine Befruchtung. 
