56 IMPORT OF THE CORPUS LUTEUM. 



But the layer of yellow matter in the recently ruptured follicle was in 

 such cases very thin, and the yellow body though in all other re- 

 spects similar to the corpus luteum of a pregnant woman, was of much 

 smaller size. It appears, therefore, that the development of the corpus 

 luteum does not proceed so far in the menstruating woman as in animals 

 in heat. The reason of this inferior degree of development of the 

 corpus luteum in the woman, in comparison with that in quadrupeds, is 

 easily conceivable ; the excitement of the ovaries and the whole sexual 

 system being undoubtedly far greater in the female quadruped in the state 

 referred to than it usually is in the human female at the period of men- 

 struation.* The degree of vascular excitement in the generative organs 

 attending the process of menstruation is moreover liable to great 

 variety. It may sometimes be only just sufficient to cause the rupture of 

 the follicle, and not adequate to the production of yellow substance by an 

 organic change in its tunic. In this way we may account for the fact that 

 in the greater number of the descriptions of ruptured Graafian follicles 

 observed in unimpregnated women, no mention is made of the existence of 

 a yellow deposit in the walls of the follicle. The follicles thus destitute of 

 yellow substance when collapsed would form the corpora albida of Dr. 

 Ritchie. On the other hand we must admit that when great excite- 

 ment attends menstruation the formation of the corpus luteum may go 

 on more rapidly and continue for a longer period, and that under these 

 circumstances the resulting yellow body may be of considerable size. 



If, in addition to the foregoing facts and considerations, the varieties in 

 size of the corpora lutea formed during pregnancy are borne in mind, it 

 will be seen that cases can seldom occur where the mere presence of one 

 of those bodies can be taken as a proof of previous impregnation. The 

 following practical rules, however, seem to be deducible from the facts 

 detailed. 



1. A corpus luteum, in its earliest stage (that is a large vesicle filled 

 with coagulated blood, having a ruptured orifice, and a thin layer of 

 yellow matter in its walls), affords no proof of impregnation having taken 

 place. 



* The fact is announced by M. Raciborski, (Acad. de M6decine, Seance du 15 Oct. 

 1844. Gaz. Med. Oct. 19, 1844,) as a deduction from his experiments and dissections, in 

 the following terms : " In the females of most of our domestic animals, whether they have 

 or have not had sexual intercourse with the males, the expulsion of the ovule is always 

 followed by the formation of a corpus luteum, a fleshy mass, of a yellow or reddish colour. 

 It is different, however, with women. If the expulsion of the ovule, at the period of men- 

 struation, is not followed by conception, the granulations on the inner surface of the Graafian 

 follicle increase in size; but this activity of nutrition soon ceases after it has produced a thin 

 membrane, of a yellow colour, lining the proper membrane of the follicle, and enclosing a 

 cavity in which traces of a clot of blood may be found. If, on the contrary, conception 

 should take place, the elements of the granular layer of the follicle continue to increase in 

 number and volume, until, in a short time, they form a mass of sufficient volume to fill the 

 whole cavity of the follicle." 



