EXTRACTS A-ND ABSTRACTS FROM FOREIGN JOURXALS. 281 



tion of the same epithelium which lines the cells. The maternal or de- 

 cidual vessels are everywhere closely applied to the surface of the villi, 

 and fill up the intervals between them. They also closely embrace the 

 foetal processes, except at their expanded summits, which, as before 

 stated, are in contact with the secretion of the glandular cells. The 

 maternal vessels, in proceeding from the uterus, first ramify on the 

 parietes of the cells, by which they are supported ; but as they approach 

 the villi and surface of the ovum, they form an abundant net- work, the 

 branches of which are unsupported by membranous structure, seemingly 

 as if the intermediate tissue of the decidua had disappeared, its vessels 

 alone remaining in the later periods of pregnancy. At parturition, the 

 decidual vessels come away with the ovum ; the parietes of the now 

 greatly enlarged glandular cells also separate in great part from the 

 uterus, leaving merely the bottoms with the round openings of the 

 glandular ducts in their centres. After separation of the ovum and 

 placenta, numerous truncated and somewhat shrivelled vessels project 

 from the inner surface of the uterus ; they are chiefly veins, and they 

 may be seen for a considerable time after parturition, on those parts 

 of the uterus to which the ova had been attached. 



From the description given, then, it follows, that in the placenta of 

 the bitch there is an arrangement by which a matter, secreted from the 

 enlarged glands of the uterus, is brought into proximity with the vessels 

 of the foetus ; and seeing that a provision of a similar nature is found 

 in various other instances, it is not improbable that in viviparous ani- 

 mals generally, a matter deposited from the maternal system by means 

 of a glandular apparatus may be absorbed into that of the foetus, and 

 serve for its nutrition ; but this is a question which can be determined 

 only after a more extended investigation. As connected with this sub- 

 ject, the source of the well-known green- coloured deposit found at the 

 borders of the placenta of Carnivora would naturally become an object of 

 inquiry ; but on this point I cannot as yet speak with certainty. 



Dr. Sharpey on the Human Decidua. These observations on the deci- 

 dua of the dog led me to examine anew the human decidua, and more 

 especially its relations to the mucous membrane of the uterus ; and I 

 shall now briefly state the result, although I find I have been in a great 

 measure anticipated by Weber, as appears from the statement of Pro- 

 fessor Miiller in the text. It is right to mention, however, that the re- 

 sults were arrived at quite independently of Weber's observations, and, 

 indeed, before the original of the pages of this work in which they are 

 noticed, reached me. 



In various instances in which there was reason to believe that impreg- 

 nation had recently taken place, and in which the ovary contained a 

 recent corpus luteum and the uterus a distinct decidual lining, though 

 no ovum had been discovered, the decidua, in some places one-tenth of 

 an inch thick, seemed obviously to consist of the thickened mucous 

 membrane. Its surface presented a multitude of small round apertures, 

 which, on a verticle section, were seen to belong to the tubular glands 

 of the mucous membrane, elongated and enlarged. These tubes were 

 lined with white epithelium, which rendered them very conspicuous 



