DR. MARTIN BARRY’S RESEARCHES IN EMBRYOLOGY. 
579 
view.) On the membrane f are represented a few of the cells of the 
tunica granulosa (g 1 ), which after fecundation become very much 
elongated, assume a club-like form, and are connected with the mem- 
brane f by their pointed extremities alone (par. 345.). The largest 
seen on this ovum measured " in length. (These cells in some in- 
stances contain a cell of considerable size, surrounded by dark globules, 
at their larger extremity. In other instances several cells are seen in 
their interior.) 100 diam. 
Fig. 196. An ovum of (not less than) sixty-six hours (par. 366.) found in the ute- 
rus, and measuring in diameter -f-. The outer surface of the mem- 
brane f (yj " — ) was very rough ; a state observed in all the ova (seven) 
found in this Rabbit. The chorion (cAo.) had thickened, imbibed a 
large quantity of thick transparent fluid (/*), and distended to the 
diameter above mentioned ; but the essential portion of the ovum — the 
two elliptical cells ( bs ) in its centre — had advanced but little more 
than the corresponding part in the ovum fig. 194, of one-sixth the age ; 
and still less than the corresponding part in the ova figs. 198 and 201. 
of only one-twelfth the age (par. 365.). (Six other ova were found in 
this Rabbit, namely, two in the uterus and four in the Fallopian tubes. 
These six were duly developed in the essential part (par. 367.). The 
inner surface of the now thickened chorion was seen in two ova from 
this Rabbit.) 100 diam. (par. 380.) 
Fig. 197. An ovum of (not less than) sixty-two hours, found in the Fallopian tube, 
half-way between its middle and the uterus. It measured in diameter 
(as much as) the chorion (cAo.) having imbibed fluid (f l ) and risen 
from the membrane f. The twin cells (bs) however — constituting the 
essential portion of the ovum — appeared less advanced than is generally 
the case at much earlier periods. With these twin cells there were 
smaller cells, presenting the same appearance as that described in the 
explanation of figs. 188 and 189; and the whole were circumscribed 
by a membrane (e), between which and the membrane f there was a 
space filled with transparent fluid. 100 diam. 
Fig. 198. An ovarian ovum of (no more than) 5| hours, measuring in diameter 
(par. 365.). It was taken from the same Rabbit as the ovum of fig. 201 . 
The two elliptic cells (bs) in its centre, constituting the essential 
portion of the ovum — that is, the germ — were more advanced than those 
in the ovum fig. 196, of no less than twelve times the age (par. 366.). 
These twin cells were not very transparent, which was perhaps owing 
to the outer portion of each of their nuclei having resolved itself into 
cells, and to their being surrounded by many dark globules. The re- 
maining portion of each nucleus contained a pellucid cavity, larger 
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