ACTION OF THE FEMALE. 



965 



existing, and of such a size as to be capable of containing a grain of wheat at 

 least, and very often of much greater dimensions ; this cavity is surrounded by 

 a strong white cyst ; and as gestation proceeds, the opposite parts of this cyst 



Corpora Lutea of different periods : B. Corpus luteum of about the sixth week after impregnation, showing 

 its plicated form at that period. 1. Substance of the ovary. 2. Substance of the corpus luteum. 3. A gray- 

 ish coagulum in its cavity ; after Dr. Patterson. A. Corpus luteum, two days after delivery. D. In the twelfth 

 week after delivery. After Dr. Montgomery. 



approximate, and at length close together, by which the cavity is completely 

 obliterated, and in its place there remains an irregular white line, whose form 

 is best expressed by calling it radiated or stelliform. This is visible as long as 

 any distinct trace of the corpus luteum remains." 1 The true corpus luteum is 

 further distinguished by its capability of being injected from the vessels of the 

 ovary ; which is not the case with tubercular deposits or other substances which 

 may simulate it. After delivery, the size of the corpus luteum rapidly dimi- 

 nishes ; and in a few months it ceases to be recognizable as such. The cicatrix 

 by which the ovum has escaped is visible for some time longer ; but this, too, 

 according to the careful researches of Dr. Montgomery, cannot be distinguished 

 at a subsequent period. Hence there is no correspondence between the number 

 of corpora lutea found in the ovaries of a woman, or of cicatrices on their surface, 

 and the number of children she may have borne. The number of corpora lutea 

 must always be less, when there have been many conceptions, in consequence of 

 the complete disappearance of some of them ; but the number of cicatrices may 

 be greater; for several causes, such as the escape of unimpregnated ova, or 

 the bursting of little abscesses, may give rise to such appearances. 



971. It is a question of much scientific interest, and one that occasionally 

 becomes of importance in Juridical investigations, what extent of resemblance 

 may exist between the condition of the Ovisac after the expulsion of an ovum 

 that does not become impregnated, and that of a pregnant female in which a 

 true " corpus luteum" is present. This question cannot be decided by observa- 

 tions on domesticated quadrupeds; since it appears certain that in them there 

 is altogether a more abundant production of the yellow substance than in the 

 Human female, and that it is more persistent after the discharge of the ovum ; 

 which may perhaps be accounted for by the greater functional activity or excite- 

 ment of the ovarian apparatus in an animal " in heat," than usually exists in 

 the Human female at the menstrual period. There is reason, moreover, to 

 believe that the amount of this may vary considerably in different females, and 

 in the same females . at different times. The general fact certainly is, that a 

 thin layer of yellow substance, composed chiefly of cells and of fibres originating 

 in the metamorphosis of cells, is ordinarily formed on the lining of the ovisac ; 

 that this is greatly increased in thickness, if the ovum be impregnated ; but that 



1 "Signs of Pregnancy," p. 226. 



