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PROFESSOR TURNER ON THE GRAVID UTERUS AND 



mare than to any other mammal, the placentation of which has been accurately 

 studied. These affinities may be briefly stated as follows : — Both animals are 

 uniparous and possess an elongated chorion, over the entire surface of which, 

 with the exception of three limited areas (two polar and one intermediate), well 

 defined villi are " diffused." In both, the amnion is studded with small cor- 

 puscles, and the umbilical vesicle disappears some time before birth. In both, 

 the allantois persists as a large sac, but whilst it preponderates over the amnion 

 in the soliped, it possesses a relatively smaller area in the cetacean. In both, 

 the highly vascular free surface of the uterine mucous membrane is crowded 

 with crypts for the reception of the villi of the chorion, and in both the utricular 

 glands are well developed; but in the mare the glands ascend with a com- 

 paratively straight stem almost vertically to the crypt-layer, whilst in the 

 cetacean they are so tortuous as to be followed with considerable difficulty to 

 their termination.'" 



Physiological Conclusions. — Finally, I may say a few words as to the physio- 

 logical conclusions to be drawn from the study of the arrangement of the 



placental structures found in this Orca. And as it may help to give one a 

 clearer insight into this important subject, I shall, in the first instance, briefly 

 summarise and illustrate, by means of the accompanying diagram, the relative 

 position of the constituent elements of the placenta in this animal. 



* Although the consideration of the placental affinities of the whale shows it to be more closely 

 allied to the mare than to any other mammal, yet I by no means wish it to be understood that in the 

 other organic systems a correspondence occurs between the cetacean and the soliped closer than can be 

 seen between them and any other class of the mammalia. For in their osteological characters, as 

 Professor Huxley has pointed out, the cetacea are allied to the true carnivora through the extinct 

 Zeuglodon and the Seals; in the possession of a compound stomach and of a third bronchus, they 

 resemble the Ruminants; in the "diffused" character of the chorion, in the presence of a vena azygos 

 (Rolleston), and in the remarkable modifications of the cerebral and intestinal arterial systems, for an 

 account of which I must refer to my memoir on the Longniddry Balamoptera, they are allied to the 

 Pachydermata. A full discussion, however, of the relative value of these characters, as determining 

 the zoological position of the cetacea, would be out of place on this occasion. 



