DR. MARTIN BARRY’S RESEARCHES IN EMBRYOLOGY. 
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the membrane / was more complete, and a globular mass, having a 
cavity in its interior, occupied the centre of the ovum (par. 337.). This 
mass consisted of elliptical compound discs, resembling those described 
in the explanation of fig. 156 (par. 337-). (The cells of the tunica 
granulosa of the ovum in the present figure had become loosened. In 
two other ova in a similar condition, from the same ovary, the mem- 
brane / presented an orifice at the part immediately above the point of 
fecundation.) 100 diam. 
Fig. 163. The pellucid centre of the altered germinal spot in an ovum from the 
same ovary which yielded the objects figs. 160. 161 and 162. (The ger- 
minal vesicle — about y/' — filled with incipient cells in concentric layers, 
resembled in position, form, and size, that (c) in fig. 162 ; but the ovum 
itself was smaller — y/'.) The space inclosed by the dotted line in the 
present figure, was pellucid and measured in diameter /o'". 300 diam. 
(par. 32/.). 
Fig. 164. An ovarian ovum of seven hours, and measuring in diameter yj". Its 
Graafian vesicle was very large. The contents of the germinal vesicle 
(c) were less pellucid than those of the germinal vesicle represented in 
fig. 162, another layer of incipient cells having come into view (par. 
326.). The objects (now cells) under the membrane / very regularly 
elliptical and flattened, were circumscribed by a proper membrane 
(pars. 338. 339. 342. 343. 360.), which at a certain part presented a de- 
pression (orifice?). This part lay immediately under an opening in the 
membrane / (pars. 332 to 335.). 100 diam. 
Fig. 165. An ovarian ovum of four hours, and measuring in diameter y/', taken 
from a Graafian vesicle which was large but not particularly vascular. 
This ovum, though smaller than that in fig. 162, resembled it in general 
appearance. The membrane /exhibited an orifice (pars. 332 to 335.) 
at the part immediately under which was situated the pellucid centre 
of the altered germinal spot — the situation of the future point of fe- 
cundation. A little external to this centre there was also a pellucid 
space. The part surrounding the latter was obscure. 100 diam. 
Fig. 166. The pellucid centre of the altered germinal spot in the ovum of the pre- 
ceding figure, as seen lying immediately under the orifice in the mem- 
brane/: with a surrounding layer of incipient cells. About 300 diam. 
(par. 328.). 
Fig. 167- An ovarian ovum of 5y hours, and measuring in diameter y/'. Its 
Graafian vesicle was vascular, but not very large. The objects cor- 
responding to those which in the ova figs. 162 and 165. lay immedi- 
ately under the membrane /, had undergone entire liquefaction — leav- 
ing a pellucid fluid in their place ; and the globular mass — correspond- 
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