of Single Hypogastric artery in the Human Foetus. 339 
I have seen an example of a symelian foetus accompanied 
by its placenta. No obviously abnormal characters could be 
detected in the latter. The specimen (which I estimate at the 
sixth to seventh month of development) is exhibited in the 
Hunterian Museum in London (Reference No. 302). That collec- 
tion contains about ten symelian monsters, in one of which the 
viscera are inverted. In none of those shewn in the galleries is 
the arterial system of the abdomen exposed by dissection, though 
there is no doubt that such preparations would render the 
specimens more instructive than they are at present. 
