1909.] VISCERA OF A WALRUS. 735 



cava in Pinnipedes and Porpoises there is, so far as I know, 

 no sphincter for cutting off the venous reservoirs from the heart, 

 and in fact if there were, it would to some extent diminish their 

 efficiency as receptacles to receive the backflow thrown into the 

 veins through the tricuspid and auricle. One is therefore led to 

 suppose that the function of the sphincter is primarily not so 

 much to relieve the pressure on the heart, as by restricting the 

 quantity of venous blood returning to the heai-t to prolong the 

 time during which such blood as is absolutely necessary for 

 the voluntary activities of the animal can be efficiently aerated. 



The generative organs. 



In the 'Journal of Anatomy' for 1900 (p. 159) Professor Cleland 

 describes the reproductive organs of a young female "Walrus and 

 draws attention in particular to the condition of the cervix and 

 corpus uteri — the part extending from the opening into the 

 vagina to the point of separation of the two cornua. This part, 

 except in those mammals in which the uteri are quite separate 



Text-fi^. 232. 



Clitoris and prepuce, seen from tlie side. 



and open by distinct oi-a into the vagina, is normally a single or 

 partly divided chamber opening below by a single os into the 

 vagina and branching above into the two cornua. This, however, 

 was not the condition found by Professor Cleland in his Walrus. 

 On the contrary the cervix uteri was divided throughout its 

 length into two distinct channels, lying side by side, separated 

 by a thick median partition and opening into the vagina by 

 separate ora situated upon a single swollen eminence. Distally 

 each uteinne chamber passed without interruption, except for a 

 slight kinking of its rugfe, into the cornu of the same side. This 

 exact condition is so seldom met with in mammals, although it 

 occurs occasionally as a rai*e anomaly in man, that Prof. Cleland 

 was doubtful whether he might not possibly have chanced upon 

 an abnormal individual. This, however, seemed less likely, as he 



