EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 283 



not, usually at least, present the same character as the vera throughout 

 its whole career ; for, without laying stress on the differences generally 

 pointed out by authors, I may state, that in various conceptions which 

 I have examined, the decidua reflexa, in a great part of its surface, was 

 destitute of the small orifices which characterise the vera, and that 

 these were confined chiefly, though certainly not entirely, to a zone of 

 the membrane adjoining the angle of reflection, that is, to the part next 

 the decidua vera. Now, if this observation be found to hold good ge- 

 nerally, it will not be necessary to suppose that the lining membrane of 

 the uterus is extended over the whole surface of the ovum to form the 

 decidua reflexa ; and although I am not prepared on such limited obser- 

 vations to offer a decided opinion, especially on a question of acknow- 

 ledged difficulty as this is, still, as at least a possible explanation, it 

 might be suggested that the minute ovum, on its entrance into the ute- 

 rus, is covered with exuded lymph, either entirely or on that part of its 

 surface which does not adhere to the inside of the uterus ; that as the 

 ovum enlarges, a circular fold of the altered mucous membrane (deci- 

 dua) is drawn up upon it, all round its adhering part, enveloping the 

 ovum to a greater or less extent, and afterwards forming the cribriform 

 zonular portion of the decidua reflexa, whilst the remaining thin smooth 

 portion of the latter membrane, which is more distant from the line of 

 reflection, and is destitute of apertures, is formed by an extension of the 

 covering lymph. Or perhaps the following more simple explanation 

 might not be inadmissible : viz. that the minute ovum, on reaching the 

 uterus, becomes imbedded in the substance of the then soft and pulpy 

 mucous membrane, and that in its subsequent enlargement it carries 

 along with it a covering of the membrane, which is expanded into the 

 decidua reflexa. 



Are the cells observed in the human decidua, by Dr. Montgomery, 

 identical with the dilated uterine glands ? Dr. M . occasionally found 

 them to contain " a milky or chylous fluid," but he does not describe 

 them as opening on the inner surface of the membrane. 



In acknowledging the kindness of my friend Dr. John Reid, now 

 Professor of Medicine in St. Andrew's, in freely placing at my disposal 

 some very valuable specimens in his collection, I deem it due also to 

 that gentleman to state, that he had previously observed the tubular 

 structure of the mucous membrane of the uterus, and was led, by an 

 examination of recently impregnated uteri, to infer that one of the 

 earliest changes which occurs after impregnation, was an increased de- 

 velopment of the tubular structure, and this he conceived was connected 

 with the formation of the decidua. At the same time, he did not sup- 

 pose that the mucous membrane was converted into the decidua, but 

 was disposed to think that the decidua was secreted by the tubes of the 

 mucous membrane." Note by Dr. Sharpey to Baly's Translation of 

 Mutter's Physiology, Lond. and Edin. Month. Journ. Med. and Science, 

 Feb. 1842. 



