DR. MARTIN BARRY’S RESEARCHES IN EMBRYOLOGY. 
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tube which had been published before the Second Series of these 
researches (par. 322.). 
Fig. 182. From Cruikshank. 
“ The figures marked third day, are ova of the Fallopian tube, found 
after impregnation on that day. The three first are of the natural 
size ; the three next are magnified, in the simple microscope. In all 
of them the chorion and amnion are even now distinct, and in some 
of them the allantois, as I suspect-^. 
“The figures marked 3^ day, are ova still more advanced; similar to 
which I found many in the tubes, many in the horns of the uterus. 
The three first are of the natural size ; the two following are mag- 
nified also in the simple microscope^;.” 
Fig. 183. From Baer. “ CEuf de chien retire de la trompe uterine. ***Grossi trente 
fois” (par. 322.) §. 
Fig. 184. From T. Wharton Jones. “ An ovum found in the Fallopian tube of a 
Rabbit the third day after impregnation ; magnified forty diameters||” 
(par. 322.). This ovum is described by Jones as having measured in 
diameter “ of an inch,” that is about y ; and being an ovum of 
“ the third day,” it admits of comparison with the delineations of ova 
in Plate XXVII. figs. 229 to 234. T. Wharton Jones conjectures “ that 
the gelatinous coat [see Plate XXIV. fig. 184.] acquired by the ovum 
in the ovary [as he supposes], and more especially circumscribed and 
defined after impregnation, constitutes the only covering of the vesicular 
blastoderma after the giving way of the vitellary membrane ; that this 
gelatinous-looking coat forms the chorion, which in the rodents at a 
further stage of development presents itself under the form of a thin 
and transparent membrane, very like the vitellary membrane of the 
bird’s egg, situated immediately outside the non- vascular and reflected 
layer of the umbilical vesicle” (/. c., p. 342.). (Contrast this with the 
description of the mode, the period, and the place of origin of the 
chorion, as given in the “ Second Series” of these researches, pars. 172. 
173. 178. 182. 221 to 225, and in the present memoir, pars. 372 to 374.) 
With reference to the interior of the ovum Plate XXIV. fig. 184, 
T. Wharton Jones remarks, “ The granulary matter of the yelk was 
coherent” (/. c., p. 339.). 
Fig. 185. An ovum of fourteen hours from the middle of the Fallopian tube ; the 
membrane f measuring in diameter r/'-l-. The outer surface of this 
membrane was covered with cells ( cho .), coalescing to form the rudi- 
t Philosophical Transactions, 1 797, p. 212. J Ibid. p. 212. 
§ Lettre sur la Formation de l’CEuf, p. 62. fig. III*. 
|| Philosophical Transactions, 1837. Part II., p. 345. 
