140 The Endocrine Organs 



the external changes characteristic of puberty either do not occur or are 

 greatly modified : there is absence of menstruation. A tendency to the male 

 type of trichosis is often also exhibited. When the operation is performed 

 subsequently to puberty the results are less marked — but menstruation 

 ceases, and there is sometimes atrophy of the mammae ; in animals a 

 diminution in size of the uterus and Fallopian tubes has been sub- 

 stantiated (Carmichael and Marshall, in rabbit ; Marshall and Jolly, in 

 white rat). According to Hatai the suprarenal capsules are diminished 

 in size in the female white rat, whereas in the male castration causes a 

 marked increase of those organs: the same author states that although 

 there is an increase in size of the pituitary, it is very slight as compared 

 with the effect of castration in the male. Metabolism is affected mainly, 

 as in males, in the direction of a tendency towards adiposity. This, 

 however, may be indirect and through other ductless glands, which are 

 affected much in the same way as they are in the male sex by removal of 

 the testicles (p. 134). 



Doubtless, as in the male sex, the effects which are produced by the 

 ovaries in determining the female secondary sexual characters are due to 

 an internal secretion. And reasoning from analogy one would be disposed 

 to refer the production of this not to the generative epithelium but to 

 special cells, like the interstitial cells above referred to. The periodical 

 changes (heat, menstruation) which occur in the female appear to be due 

 neither to the Graafian follicles nor to the corpora lutea. For heat in 

 animals still occurs if the corpora lutea are destroyed, or if none are 

 present in the ovary. Moreover, the changes which follow spaying can 

 be prevented by ovarian grafts, and these may contain no corpora lutea. 

 The grafts may also show after a time no Graafian follicles — these having 

 undergone degeneration and disappearance. 1 And even in the absence of 

 Graafian follicles from the implanted ovarian tissue, Marshall and Jolly 

 and A. L. MTlroy have shown that the atrophic changes in the uterus which 

 ordinarily follow spaying are prevented by the graft. 



1 This is not, however, a necessary consequence of reimplantation, for instances are 

 recorded of development of Graafian follicles and formation of corpora lutea, or even of the 

 supervention of pregnancy, after reimplantation of ovaries in spayed animals. Such an 

 occurrence in the case of a woman has been reported by Halliday Croom. 



