160 



inasmuch as the 'serotina' and 'reflexa' in man are situated on 

 the anti-mesometric side of the uterus. At the same time I think 

 that a comparison might fairly be instituted between the 'decidua 

 reflexa' and the anti-mesometric thickening embracing the pit 

 in which the mouse embryo is fixed. 



Secondly, Duval does not appear to have noticed the presence 

 of fat in the epithelium of the uterus and its glands, nor [in the 

 cells of the proximal wall of the yolk-sac; and I cannot agree 

 with him in attributing a secretory, rather than au absorptive 

 function to the last mentioned ; in the Rabbit and the Guinea 

 Pig he has quite rightly recoguised the physiological importance of 

 the yolk-sac as an orgau of absorptiou. He makes no allusion to 

 the presence of fat and other granules in the megalokaryocytes, 

 nor to the transitory vacuolation of the layer of flattened cells 

 immediately adjacent to the embryonic pit, nor to the presence 

 of glycogen, although he has described the 'vesicular' cells which 

 secrete this substance; and, further, I do not consider that he 

 is quite correct when he limits nuclear division to the cellular 

 layer of the trophoblast, and regards the upper syncytial portion 

 as doomed quickly to disappear. 



I have certainly found mitoses in this portion, and the débris 

 which he describes as resulting from its degeueration must, I 

 think, be due to the disorganisation of adjacent maternal tissues; 

 I quite agree with him of course with respect to the ultimate 

 disintegration of the megalokaryocytes. Again, I canuot accept 

 his statement that at the end of placentation the plasmodium 

 covering the foetal capillaries disappears ; I have examined the 

 actual after-birth, and found the layer in question still present. 



Lastly he has apparently not seen the central arteries in the 

 allantoidean region in an early stage (when they are frequently 

 very small) while he has, in describing the blood supply of the 

 placenta at a later period, made the somewhat astonishing state- 

 ment that the central blood channels are efferent; he says in 

 effect (p. 526): 'les injections sont tres démonstratives a eet 

 égard, et elles nous apprennent notamment que parmi les con- 



