784 GENERATION. 



ble, although there is always a gelatinous exudation more or less colored 

 with blood. At the same time the follicular wall undergoes hypertrophy, 

 and it becomes convoluted, or folded, and highly vascular. This convoluted 

 wall, formed by the proper coat of the follicle, is surrounded by the fibrous 

 tunic, and its thickening is most marked at the deepest portion of the follicle. 

 At the end of about three weeks, the body which is now called the corpus 

 luteum, on account of its yellowish or reddish- yellow color has arrived at 

 its maximum of development and measures about half an inch (12*7 mm.) in 

 depth, by about three-quarters of an inch (19*1 mm.) in length, its form being 

 ovoid. The convoluted wall then contains a layer of large, pale, finely granu- 

 lar cells, which are internal and are supposed to be the remains of the epithe- 

 lium of the follicle. The great mass of this wall, however, is composed of 

 large, nucleated cells, containing fatty globules and granules of reddish or 

 yellowish pigmentary matter. The thickness of the wall is about one-eighth 

 of an inch (3*2 mm.) at its deepest portion. 



After about the third week the corpus luteum begins to contract; its 

 central portion and the convoluted wall become paler ; and at the end of 

 seven or eight weeks, a small cicatrix marks the point of rupture of the 

 follicle. 



The above are the changes which occur in the Graafian follicles after 

 their rupture and the discharge of ova, when the ova have not been fecun- 

 dated ; and the bodies thus produced are called false corpora lutea, as distin- 

 guished from corpora lutea formed after conception, which latter are called 

 true corpora lutea. 



Corpus Luteum of Pregnancy. When a discharged ovum has been fecun- 

 dated, the corpus luteum passes through its various stages of development 

 and retrogression much more slowly than the ordinary corpus luteum of 

 menstruation. The retrogression begins toward the end of the third month. 

 " During the fourth month, the corpus luteum diminishes by nearly a third, 

 and toward the end of the fifth, it ordinarily is reduced one-half. It still 

 forms, however, during the first days after parturition, and in the greatest num- 

 ber of cases, a tubercle which has a diameter of not less than f to ^ of an inch 

 (7-3 to 8-5 mm.). The tubercle afterward diminishes quite rapidly; but it 

 is nearly a month before it is reduced to the condition of a little, hardened 

 nucleus, which persists more or less as the last vestige of a process so slow in 

 arriving at its final term. Nevertheless, there is nothing absolute in the 

 retrograde progress of this phenomenon. I have seen women, dead at the 

 sixth and even the eighth month of pregnancy, present corpora lutea as 

 voluminous as others at the fourth month " (Coste, 1849). The differences 

 between the corpora lutea of pregnancy and of menstruation were accurately 

 described by Dalton, in 1851 and 1877. 



MALE ORGANS OF GENERATION. 



The chief physiological interest attached to the anatomy of the male or- 

 gans of generation relates to the testicles, which are the organs in which the 

 male element of generation is developed. As regards the penis, it will be 



