16 RICHARD ASSHETON AND THOMAS G. STEVENS. 
arranged as though forming a capsule round the middle 
region (cap.). 
There are blood vessels, mostly capillaries, which are more 
numerous towards the chorionic surface. Only very few 
nuclei lie embedded among the fibres, and these are chiefly 
near the surface. Most of the nuclei one sees are nuclei of 
the endothelium of the capillaries. 
Turner evidently regarded these as corresponding to the 
structures in the mare and pig, which gives rise to the ‘‘hip- 
pomanes ” in the former. On the chorionic surface there are 
curious small protuberances, with constricted stalks, which are 
especially vascular (v, fig. 10), and are probably minute villi, 
although in the specimen which we had there is no trace of a 
trophoblastic epithelium. 
It seems to us extremely doubtful whether these structures 
are comparable to the hippomanes producing bodies. The 
capsule-like internal structure suggests an origin comparable 
to the curious recesses described by Hubrecht in the diffuse 
non-deciduate placenta of alemur. [Hubrecht in his Spolia 
Nemoris on Nycticebus Tardigradus. ] 
Section II. 
Histology of the “Half-term” Placenta. 
Owen’s specimen was supposed by him to be of about half- 
term, though Chapman considered it to be of not more than 
six months. 
In spite of the fact that it has been over fifty years in 
spirit, it is possible to make out a good deal from certain 
parts. The more central parts are less well preserved, and 
have shrunk, but the edges are remarkably good and of very 
ereat interest. 
The central part resembles in all essential points the con- 
dition already described for the full-term placenta, but between 
the centre and the edges we find conditions which have every 
