280 EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 



as their relation to the membranes of the foetus, I beg to subjoin an out- 

 line of my observations. 



The glands of the mucous membrane of the bitch's uterus are of two 

 kinds, simple and compound, The simple glands, which are the more 

 numerous, are merely very short unbranched tubes closed at one end. 

 The compound glands have a long duct, dividing into convoluted 

 branches ; both open on the inner surface of the membrane by small 

 round orifices, lined with epithelium and set closely together. After 

 impregnation, the parts of the mucous membrane which come into im- 

 mediate relation with the ova, together with the glands seated in those 

 parts, undergo a remarkable alteration. In a uterus between three and 

 four weeks after conception, at which period the dilatations or chambers 

 which contain the ova attained the size of a walnut, we find, on laying 

 open one of the chambers, that the lemon- shaped ovum is surrounded 

 by a broad belt or zone of villi, which rise from the surface of the cho- 

 rion, and, becoming vascular, take part in the formation of the zonular 

 placenta. Corresponding with this, there is a zonular portion of the 

 inner surface of the uterus, somewhat raised above the rest, and perfo- 

 rated with small pits, into which the foetal villi are received ; and as 

 this part of the membrane enters into the formation of the placenta, 

 and comes away with the ovum at parturition, it is justly regarded as 

 the decidua. The decidua is no new structure, however ; it is merely a 

 portion of the mucous membrane become more thick and vascular than 

 the rest, and the pits on its surface, which receive the foetal villi, are 

 merely the glands already mentioned somewhat enlarged and widened. 

 While, however, the simple glands merely undergo a uniform enlarge- 

 ment, a change takes place in the compound glands of a much more 

 remarkable character. The long excretory ducts of those glands, imme- 

 diately before they open on the inner surface of the membrane, become 

 dilated into cells, one for each gland, which are filled with a semi-fluid 

 whitish granular secretion, and are lined with epithelium. These cells 

 form a layer beneath the surface of the decidua, and being crowded to- 

 gether, assume a polyhedral form. At the bottom of each, the tubular 

 duct may be seen about to expand into the cell, and the cell again con- 

 tracts at its orifice. 



In a somewhat more advanced stage, the glandular cells enlarge, their 

 orifices expand, and now membranous processes rise from the surface 

 of the ovum and enter the glandular cells, passing a little way beyond 

 the orifices, by the circumference of which they are embraced. These 

 foetal processes are prolonged from the chorion and its vascular lining 

 or endochorion, and hence contain ramifications of the umbilical vessels. 

 They are for the most part hollow or saccular, at least at first, and some 

 of them present, for a time, a small aperture of communication between 

 their cavity and the general sac of the chorion, or rather of its vascular 

 lining, but this is soon obliterated ; ultimately, they come to resemble 

 much the villi in structure, differing only in size and form. As preg- 

 nancy advances, the parts described enlarge, the villi become more com- 

 plex by rammification, the foetal processes also give off numerous lateral 

 offsets ; but their broad flattened tops, which close the mouths of the 

 glandular cells, are smooth and even, and are covered with a prolonga- 



