CHAP. XXXIX.] TRUE AND FALSE CORPORA LUTE A. 567 



sometimes forms a very remarkable prominence on the surface of 

 the ovary. 



The corpus luteum of menstruation is smaller than that following 

 conception ; its yellow colour appears very rapidly, and soon fades. 

 In the course of one or two months, after their first appearance, 

 they are no longer to be distinguished. Virgin corpora lutea are 

 not vascular, and cannot be injected. 



If a section of the corpus luteum be made, a small cavity will be 

 found in the interior, from which several lines appear to radiate 

 towards its external surface. This little cavity gradually contracts, 

 and ultimately disappears. According to Dr. Montgomery, within 

 the first three or four months of pregnancy, the cavity is large 

 enough to contain a grain of wheat, and often much larger. The 

 same observer has always found the cavity absent after the sixth 

 month ; usually it seems to disappear between the fourth and fifth 

 months. A few months after delivery, the corpus luteum entirely 

 disappears. Dr. Montgomery never saw one later than the end 

 of the fifth month after delivery. 



In a medico-legal point of view, the characters of the corpus 

 luteum are sometimes of great importance, and it will be well to 

 recapitulate the most important. The true corpus luteum of 

 pregnancy possesses very well marked characters, by which it 

 may be distinguished from the false corpus luteum. 



Its projection from the surface of the ovary : its large size, often 

 equal to that of a mulberry, and its rounded form ; the triangular 

 depression and cicatrix upon its surface ; the little cavity in its 

 centre during the earlier period of its formation, or the stellate 

 cicatrix during the latter part of pregnancy; its lobulated or 

 puckered appearance ; its firm consistence and yellow colour ; its 

 great vascularity, as may be shown by injection, and its persistence 

 for some time after delivery, are all important points in which the 

 true corpora lutea contrast remarkably with those which are formed 

 where conception has not taken place. The false corpora lutea are 

 small in size, and do not project from the surface of the ovary ; 

 they are often angular in form, seldom present any external 

 cicatrix, contain no cavity or stellate marking in the centre j 

 the material of which they are composed is not lobulated, and 

 their consistence is usually very soft ; they often resemble coagu- 

 lated blood ; the yellow material exists in the form of a very thin 

 layer, or, as is more commonly the case, not a trace of this sub- 

 stance is present. False corpora lutea are easily broken down, and 

 often consist either of small cysts, containing serum, or of a simple 

 coagulum. 



