28 RICHARD ASSHETON AND THOMAS G. STEVENS. 
down, so to speak, the lateral bands of the belt whose smooth 
maternal surface indicates but slight means of attachment. 
A similar function amongst others must be assigned to the 
long villi which pierce region C and enter the uterine walls. 
Although there is an obvious resemblance between the 
elephant’s placenta and the zonary placenta of the Carnivora, 
and even between the meandering character which we have 
described, and the labyrinthine lamelle of the dog or cat’s 
placenta, yet we believe that this resemblance is superficial— 
for in reality the two types are very different. 
Bearing in mind the possibility of affinity between 
Ungulates, Carnivora, and Proboscidea through some such 
forms as Phenacodus, it is especially interesting to compare 
the placenta in these three types. 
Firstly, the elephant’s placenta diifers from that of the dog 
in having a distinctly non-deciduous part, which resembles 
closely the diffuse type of the mare. 
The carnivorous placenta is a broad central band leaving 
the two poles bare, while in the elephant the central band is 
comparatively narrow, and the poles are villous, leaving two 
broad bare zones between the poles and the central deciduous 
belt. 
There is in the carnivora nothing comparable to long villi 
which pass through the “ coagulum” region and extend deep 
into the maternal tissues, and are, so far as the projecting 
parts of the villi are concerned, non-deciduate. 
There is no sign in the elephant’s placenta of anything like 
the angio-plasmode. ‘The mode of vascularisation of the 
after-birth is quite different in the two types. 
In the Carnivora the trophoblast advances into the maternal 
tissues according to Duval and surrounds the maternal 
capillaries. Other authors, Strahl, Fleischmann, Heinricius, 
etc., give different accounts, but in no case is there anything 
comparable to the conditions we find in the elephant, where 
the trophoblast is comparatively imactive and extravasated 
blood from the maternal system seems to force its way between 
the mother and foetus and ultimately into the trophoblastic 
