54 THE SEX-COMPLEX 



Effects of observations be correctly interpreted, is one of consider- 

 thyroi&ec- gfole interest, for it brings forward evidence that the 

 ovaries. granulosa cells of the Graafian follicle form an organ 

 of internal secretion. But we have already seen (p. 47) 

 that the follicular secretion is not necessarily connected 

 Effects of with the integrity of the uterus, and the effect of thyroid- 

 tomy^the ectomy gives further confirmation of this fact, for 

 uterus. after thyroidectomy the uterus atrophies to a remark- 



able extent. Figure 14 is a section of the uterus of 

 a normal cat, while figure 25 that of a cat after 

 thyroidectomy. It will be observed that the uterus 

 of the thyroidectomized cat shows very considerable 

 muscle - atrophy, almost as much as occurs after 

 oophorectomy (fig. 15). In the case illustrated the 

 cat was pregnant when the thyroid was removed, and 

 the kittens were born two days later. The animal died 

 eventually at the end of a month. The condition might, 

 therefore, be described as one of superinvolution. But 

 the same effect on the uterus is to be observed in the 

 non-pregnant animal after removal of the thyroid. 

 The importance of this atrophy will be considered 

 more fully later ; for, before drawing our final con- 

 clusions from these results, it will be advisable to take 

 into account the clinical observations that have been 

 made in regard to insufficiency of the thyroid (Part II). 



EFFECTS OF THYROIDECTOMY ON THE SUPRAItENALS 



The normal suprarenal structure is well known, but 

 I must refer to it briefly in order better to illustrate the 

 changes that occur, physiologically and pathologically, 

 Structure of in the cat. The suprarenal is divided into two parts, 

 suprarenal, the cortex and the medulla. These have, apparently, 

 different physiological functions when examined ex- 

 perimentally. The extract of the medulla produces 

 the pressor effect of suprarenin, while that of the 

 cortex is inactive. Abelous 1 and his associates 



1 Abelous, J. E., A. Soulie, and G. S. P. Toujan, Compt. Rend, Soc. 

 Biol, 1905, vol. lvii, pp. 530, 533, 574. 



