598 
MR. LUBBOCK ON THE OBNEEATIVE OEOANS, AND 
oval form. At the free end of each follicle, opposite its place of attachment to the 
stroma, is a place deficient in epithelial cells, the space being apparently occupied by a 
thick layer of some amorphous substance. 
The specimens which I examined in July and August contained some eggs -^th of 
an inch in diameter, and of an opake white appearance, with others in all earlier stages 
of development. 
I was not able to ascertain with certainty the origin of the Purkinjean vesicle; but in 
the youngest egg-follicle it only differed in size and in the solid appearance of the nucleus 
from the ordinary epithelial cell. I have therefore little doubt that the Purkinjean 
vesicle is a modified epithelial cell, and that the “ macula ” of Wagner is homologous 
with its nucleus. The smallest Purkinjean vesicle I observed was gg^op th of an inch in 
diameter, the follicle itself being only about double the size. The macula was distinctly 
visible ; and neither in this one, nor in others rather more advanced, could I see the 
vitelligenous bodies. 
The young egg-follicles, at a somewhat later stage, strikingly resemble those of Coccus 
before the constriction has commenced and when the epithelial cells are not very con- 
spicuous ; and this similarity is the more striking because we find in Glomeris vitelli- 
genons bodies (Plate XVI. figs. 1 & 2, -?;) like those of insects, and specially like those 
of Coccus. The size and number is certainly more variable, but not in any great degree, 
five or six being the largest, and three or four the commonest number, and the usual 
relative size being also that which is generally found in Coccus. The yelk-substance is 
at this period more or less clear and transparent, and no oil-globules have been formed 
in it, so that the Purkinjean vesicle and spot are easily seen (Plate XVI. fig. I,^); the 
vitelligenous bodies, on the contrary, so nearly resemble the yelk-substance in colour 
and consistence, that only in a few instances their outlines can be perceived, and then 
only in part and mth difficulty. 
This apparent similarity, however, does not prove any'real identity of composition, as 
may readily be shown by the addition of a little acetic acid. No sooner is this done, 
than the yelk-substance becomes considerably darkened ; and as the vitelligenous bodies 
remain unaltered, the contrast makes them very clearly visible ; so that if a number of 
egg-follicles are in the field of view, the difference which is thus effected in their appear- 
ance is very striking (Plate XVI. fig, 2). As usual, the acetic acid renders the cell-wall 
of the Purkinjean vesicle almost invisible, and wipes out, as it were, the macula; but the 
contrast of colour leaves the vesicle itself very plain. 
Under this treatment the Purkinjean vesicle very much resembles a vitelligenous cell, 
though it is generally rounder ; and if the acid has been very weak, the ghost, so to say, 
of a macula may still be perceived, and sometimes a very similar nucleus may be seen 
in some of the vitelligenous bodies. This very seldom liappened ; but I have figm-ed 
one of the few cases observed, in Plate XVI. fig. 2. Perhaps, therefore, in Glomeris 
the vitelligenous body is homologous with the Purkinjean vesicle, and the nucleus of 
the one with the macula of the other. According, however, to Meyer’s obsei*vations, it 
