ened from the deposition of a reddish-yellow, glutinous substance, a product of cell growth from the proper coat of the follicle and the membrana granulosa. After the ovum escapes, there is usually a small effusion of blood into the cavity of the follicle, which soon coagulates, loses its coloring matter, and acquires the characteristics of fibrin, but it takes no part in the formation of the corpus luteum. The walls of the follicle become convoluted, vascular, and undergo hypertrophy, until they occupy the whole of the follicular cavity. At its period of fullest development, the corpus luteum measures three fourths of an inch in length and half an inch in depth. In a few weeks the mass loses its red color, and becomes yellow, constituting the corpus luteum, or yellow body. It then begins to retract and becomes pale; and at the end of two months nothing remains but a small cicatrix upon the surface of the ovary. Such are the changes in the follicle if the ovum has not been impregnated. The corpus luteum, after impregnation has taken place, undergoes a much slower development, becomes larger, and continues during the entire period of gestation. The difference between the corpus luteum of the unimpregnated and pregnant condition is expressed in the following table by Dalton : Corpus Luteum of Menstruation. Corpus Luteum of Pregnancy. Three-quarters of an inch in diameter; central clot reddish; convoluted wall pale. At the end of three weeks. One month. Two months. Four months. Smaller; convoluted! Larger; convoluted wall wall bright yellow; clot bright yellow; clot still redstill reddish. dish. Reduced to the condi. tion of an insignificant cicatrix. Absent or unnoticeable. GENERATIVE ORGANS OF THE MALE. The Generative Organs of the Male consist of the testicles, vasa deferentia, vesiculæ seminales, and penis. The Testicles, the essential organs of reproduction in the male, are two oblong glands, about an inch and a half in length, compressed from side to side, and situated in the cavity of the scrotum. The proper coat of the testicle, the tunica albuginea, is a white, fibrous structure, about the 15 of an inch in thickness; after enveloping the testicle, it is reflected into its interior at the posterior border, and forms a vertical process, the mediastinum testes, from which septa are given off, dividing the testicle in lobules. The substance of the testicle is made up of the seminiferous tubules, which exist to the number of 840; they are exceedingly convoluted, and when unraveled are about 30 inches in length. As they pass toward the apices of the lobules they become less convoluted, and terminate in from 20 to 30 straight ducts, the vasa recta, which pass upward through the mediastinum and constitute the rete testis. At the upper part of the mediastinum the tubules unite to form from 9 to 30 small ducts, the vasa efferentia, which become convoluted, and form the globus major of the epididymis; the continuation of the tubes downward behind the testicle and a second convolution constitutes the body and globus minor. The seminal tubule consists of a basement membrane lined by granular nucleated epithelium. The Vas Deferens, the excretory duct of the testicle, is about two feet in length, and may be traced upward from the epididymis to the under surface of the base of the bladder, where it unites with the duct of the vesicula seminalis, to form the ejaculatory duct. The Vesiculæ Seminales are two lobulated, pyriform bodies, about two inches in length, situated on the inner surface of the bladder. They have an external fibrous coat, a middle muscular coat, and an internal mucous coat, covered by epithelium, which secrets a mucous fluid. The vesiculæ seminales serve as reservoirs, in which the seminal fluid is temporarily stored up. The Ejaculatory Duct, about 3/4 of an inch in length, opens into the urethra, and is formed by the union of the vasa deferentia and the ducts of the vesiculæ seminales. The Prostate Gland surrounds the posterior extremity of the urethra, and opens into it by from twenty to thirty openings, the orifices of the pros GENERATIVE ORGANS OF THE MALE. The Generative Organs of the Male consist of the testicles, vasa deferentia, vesiculæ seminales, and penis. The Testicles, the essential organs of reproduction in the male, are two oblong glands, about an inch and a half in length, compressed from side to side, and situated in the cavity of the scrotum. The proper coat of the testicle, the tunica albuginea, is a white, fibrous structure, about the of an inch in thickness; after enveloping the testicle, it is reflected into its interior at the posterior border, and forms a vertical process, the mediastinum testes, from which septa are given off, dividing the testicle in lobules. The substance of the testicle is made up of the seminiferous tubules, which exist to the number of 840; they are exceedingly convoluted, and when unraveled are about 30 inches in length. As they pass toward the apices of the lobules they become less convoluted, and terminate in from 20 to 30 straight ducts, the vasa recta, which pass upward through the mediastinum and constitute the rete testis. At the upper part of the mediastinum the tubules unite to form from 9 to 30 small ducts, the vasa efferentia, which become convoluted, and form the globus major of the epididymis; the continuation of the tubes downward behind the testicle and a second convolution constitutes the body and globus minor. The seminal tubule consists of a basement membrane lined by granular nucleated epithelium. The Vas Deferens, the excretory duct of the testicle, is about two feet in length, and may be traced upward from the epididymis to the under surface of the base of the bladder, where it unites with the duct of the vesicula seminalis, to form the ejaculatory duct. The Vesiculæ Seminales are two lobulated, pyriform bodies, about two inches in length, situated on the inner surface of the bladder. They have an external fibrous coat, a middle muscular coat, and an internal mucous coat, covered by epithelium, which secrets a mucous fluid. The vesiculæ seminales serve as reservoirs, in which the seminal fluid is temporarily stored up. The Ejaculatory Duct, about 3/4 of an inch in length, opens into the urethra, and is formed by the union of the vasa deferentia and the ducts of the vesiculæ seminales. The Prostate Gland surrounds the posterior extremity of the urethra, and opens into it by from twenty to thirty openings, the orifices of the pros |