62 
DR. LEE ON THE STRUCTURE OF THE HUMAN PLACENTA, 
made for the purpose of proving or disproving the fact that the deciduous mem- 
brane passes over the uterine surface of the placenta ; but in reference to pre- 
paration R. R. No. 139, it is observed by Dr. Nimmo that no vascular openings 
are visible in the membrane interposed between the uterus and placenta. 
No. 178. “is a small section of the uterus with the veins injected green, and 
broken off where they were entering the placenta.” The surface of the injected 
matter is smooth ; the edges of the openings defined and quite unlike ruptured 
vessels ; their form in general elliptical, seeming as if they were holes cut in 
the side of a convolution. 
No. 125. “A portion of uterus and placenta, the latter injected from uterine 
vessels.” There is an opening which seems to be natural, corresponding to one 
of those in the uterus; but the majority of those whereby the injection has 
passed into the placenta seem to be mere lacerations. 
No. 101. “A section of uterus with veins injected black, and the injected 
matter protruding by irregular plugs into the cavity of the uterus.” The holes 
are semilunar and elliptical, with defined edges, and nothing resembling the 
continuation of vascular tubes to be seen. 
R. R. 121. is described in the printed Catalogue as follows : “ A small por- 
tion of placenta and uterus where the cells of the placenta have been injected 
from the veins of the uterus. The veins are seen very large, entering the sub- 
stance of the placenta.” 
Dr. Nimmo makes the following observations on this specimen : “ This prepa- 
ration seems to be most in point. I would describe it differently. The cellular 
substance of the placenta has certainly been filled from the uterine vessels. 
These, however, instead of passing directly into the placenta, are distinctly 
seen applying their open mouths to the membrane of the placenta, where the 
injection in some instances stops. The membrane is thinner here than where 
no vessels are applied, consisting, so to describe it, of one layer, w T hile a second 
layer covers all other parts. Where the injection has passed into the substance 
of the placenta, it has evidently been forced to the side between the layers, and 
found some weak point, whereby it has entered into and been diffused through- 
out the cellular texture of the placenta*.” 
* My friend Samuel Broughton, Esq., F.R.S., during a recent visit to the Hunterian Museum at 
Glasgow, examined the preparations of the placenta and uterus at my request, and authorizes me to 
say that his observations fully confirm the accuracy of Dr. Nimmo’s statements. 
