572 
DR. MARTIN BARRY’S RESEARCHES IN EMBRYOLOGY. 
ing to that which in the ova figs. 162 and 165. consisted of regularly 
elliptical compound discs — exhibited in the present ovum an irregular 
structure, the cells, into which its discs had passed, appearing to have 
become pressed into irregular shapes, or partially broken down ; and the 
mass they constituted was distinctly circumscribed by a membrane, e 
(pars. 338. 339. 342. 343. 360.). Of the germinal vesicle (c) nothing 
could be distinctly seen besides its outline, and the pellucid centre of 
the altered germinal spot. This centre lay immediately under an ori- 
fice in the membrane /’(pars. 332 to 335.). In this orifice an object 
was observed resembling a Spermatozoon in the act of entering the 
ovum (par. 334.). (Part of this object is represented in the next figure.) 
The orifice was very obvious in this ovum, and seen with more or less 
distinctness in five other ova of the same Rabbit. 100 diam. 
Fig. 168. The large extremity of the object resembling a Spermatozoon, observed 
in the orifice of the membrane /'in the preceding figure. It presented 
in its interior a pellucid point, similar to that seen in certain states of 
the germinal spot, and in the elliptical discs which occur in so many 
figures accompanying the present paper (par. 334.). About 300 diam. 
PLATE XXIII. 
All the Figures are from the Rabbit ( Lepus Cuniculus , Linn.). 
Fig. 169. A fecundated ovarian ovum of hours, and measuring in diameter 
Ts "' — . (Its Graafian vesicle was large and vascular.) The germinal 
vesicle (c) — filled with cells (pars. 329. 382.) — appeared to be returning 
to the centre of the ovum. It is probable that the ovum had only just 
been fecundated, for the point of fecundation was still at the surface of 
the germinal vesicle. (It subsequently passes to the centre.) (par. 341.) 
The substance contained within the membrane f seemed to be sur- 
rounded by a proper membrane, e (pars. 338. 339. 342. 343. 360.). 
The membrane /*was distinctly cleft above the point of fecundation 
(pars. 332 to 335.). (The cells of the tunica granulosa had become 
club-shaped, and radiated from the ovum in the manner shown at 
in figs. 173. 181 and 195 (par. 345.). The tunica granulosa also 
exhibited a depression similar to that represented in fig. 173, this being 
apparently the effect of pressure towards the exterior of the ovary.) 
100 diam. 
Fig. 170. A fecundated ovarian ovum of 8|- hours, and measuring in diameter fM. 
This figure presents a superficial view of the ovum. The germinal ve- 
sicle had left the surface of the ovum, but its situation was not quite 
central. It had become closely surrounded by cells, each of which pre- 
