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IV. Spermatozoa observed within the Mammiferous Ovum. 
By Martin Barry, M.D . , F.R.SS. L. and E. 
Received November 24, — Read December 8, 1842. 
As the results of my researches in Embryology have all been communicated to the 
Royal Society*, it seems proper to offer to its notice a single observation which I 
have lately made. 
On a former occasion -f- I stated that at certain periods an orifice was sometimes 
visible in the thick transparent membrane (“zona pellucida ”) of the mammiferous 
ovum ; and that once I had seen an object very much resembling a spermatozoon in 
the orifice. But spermatozoa, so far as I am aware, have never been described as 
seen within the ovum of any animal. It may therefore be interesting to physiologists 
to be informed that about a fortnight since, in examining some ova of the Rabbit of 
twenty-four hours, from the Fallopian tube, — in which the orifice above-mentioned 
was no longer visible, — I unexpectedly discerned a number of spermatozoa in their 
interior. These ova were submitted to the inspection of Professor Owen, and I after- 
wards showed one of them to Professors Sharpey and Grainger, all of whom agreed 
that the spermatozoa were contained within the ovum\. 
London , 21 st November, 1842 . 
* Philosophical Transactions, 1838-39-40-41. f Ibid. 1840, p. 533. 
t [The ova yere in that state in which the essential part — the germ — consists of two cells. The spermatozoa 
lay around and between these cells ; and when the ova were first examined I thought I discerned traces of 
spermatozoa even within the cells. 
While the paper is going through the press, the opportunity is afforded me for mentioning that I have 
this day confirmed the observation above recorded ; several ova from the Fallopian tube of another rabbit, in a 
somewhat earlier stage, having presented spermatozoa in their interior ; — i. e. (as in the first observation) within 
the thick transparent membrane (“ zona pellucida”) brought with the ovum from the ovary. — 31st March, 1843.] 
MDCCCXLIII. 
F 
