578 
DR. MARTIN BARRY’S RESEARCHES IN EMBRYOLOGY. 
undergoing liquefaction. Internal to them was a delicate vesicle c, 
apparently the germinal vesicle enlarged to the diameter of about 
This vesicle contained, on the inner surface of its membrane, cells of 
considerable size, apparently liquefying. These surrounded a layer of 
minuter ones, having their nuclei in some instances on one side ; and 
these minuter cells seemed also to be circumscribed by a delicate 
membrane (par. 349 Note, 360.). In the most internal part there were 
two large cells ( bs ), corresponding to those occupying the centre of the 
ova figs. 187 and 191. These twin cells — the essential portion of the 
ovum, that is, the germ — were of about the same size in length) 
as those in fig. 191, but they were less transparent ; a difference which 
perhaps arose from the outer portion of their nuclei having resolved 
itself into cells (see the explanation of fig. 192.), while another layer of 
the foundations of new cells, arisen in the interior (and presenting also 
the appearance of a nucleus) had succeeded it (par. 380.). (The ovum 
was surrounded by transparent fluid. Possibly this fluid arose from 
liquefaction of the tunica granulosa and retinacula). 100 diam. 
PLATE XXV. 
All the Figures are from the Rabbit ( Lepus Cuniculus, Linn.). 
Fig. 194. An ovum of eleven hours, found half-way between the infundibulum and 
the middle of the Fallopian tube, and measuring in diameter t^"'. It 
was taken from the same Rabbit as the ova in figs. 195 and 199. The 
central portion of this ovum differed from that of the ovum fig. 193. in 
the following respects ; namely, the twin cells (bs ) — constituting the 
germ — were somewhat larger, and no vesicle was seen corresponding 
in appearance to c in that figure. The nuclei of the cells which closely 
invested the germ, seemed to be situated (as in the ovum fig. 193.) on 
one side of their cells. 100 diam. (par. 380.) 
Fig. 195. An ovum of eleven hours, found at two-thirds of the distance between 
the infundibulum and the middle of the Fallopian tube, and measuring 
in diameter It was taken from the same Rabbit as the ova figs. 
194 and 199. This ovum appeared to be in a state resembling that of 
the ovum fig. 193. The delicate vesicle c — apparently the enlarged 
germinal vesicle, now irregular in its form — measured in diameter 
On the inner surface of the membrane of this vesicle were cells of con- 
siderable size, having minuter ones between them. (Two large cells 
— constituting the germ — occupied the most central part. They are 
not shown in the present figure, because of its exhibiting a superficial 
