822 THE ENDOCRINE ORGANS, OR DUCTLESS GLANDS 



sexual characteristics, and that these may recede after the removal of 

 the tumor. 



As a result of castration, interesting changes have also been observed 

 in other ductless glands. Thus, the suprarenal cortex and the thymus 

 become enlarged, whereas the thyroid and pituitary become atrophied. 

 The metabolic functions also become tardy, as is evidenced by a tendency 

 to the deposition of fat. 



When the castration is performed on an adult man, the above changes 

 in the. sexual characteristics are of course not so evident, although the 

 prostate, etc., atrophy. The effect on the metabolic functions is, how- 

 ever, very marked, there being a striking tendency to increased forma- 

 tion of fat. It is interesting that accompanying this there should usually 

 occur a lowering of the assimilation limit for carbohydrate, so that glyco- 

 suria is very readily induced. We can not assume, therefore, as Gush- 

 ing has done in the case of hypopituitarism, that the fat deposition is 

 attendant upon an improper combustion of carbohydrate. 



These remarkable effects of castration have naturally prompted ob- 

 servers to study the influence of injection of testicular extract on the 

 development of sexual characteristics in different animals, but the re- 

 sults have in general been considered to be of a negative character. 



The Female Generative Organs 



It is well known that, besides their function in producing ova, the 

 ovaries also produce autacoids that have to do not only with the fixa- 

 tion of the embryo in utero, but also with the changes that occur during 

 pregnancy in the maternal organism. It is however at present uncertain 

 as to where these autacoids are produced in the ovary. The two most 

 likely sources are the stroma cells and the corpus luteum. In the stroma 

 of the ovary of certain animals, groups of cells have been described 

 having a different appearance from those of ordinary stroma cells. 

 They have been called the interstitial cells of the ovary, and are believed 

 to be analogous with the similar structures found in the testicle. It is 

 possible, however, that these interstitial cells are nothing more than 

 cells derived from previous corpora lutea. The latter are formed by 

 proliferation of the follicular epithelium which remains after extrusion 

 of the ovum, and by the ingrowing into the follicle of the so-called theca 

 cells and blood vessels. The fully developed corpus luteum in most 

 animals consists of cells arranged in trabeculae converging toward the 

 scar which formed at the place where the follicle had burst. The luteal 



