THE EHYTHM OF GONADAL FUNCTION 575 



which the overwhelming proportion of the tissue consists of inner thecal 

 or interstitial cells. These authors admit, however, that certain of the 

 follicular granulosa cells survive and enlarge. Sand, who has found more 

 normal structures in the ovarian transplant, nevertheless describes an 

 increase of atretic processes, so that internal thecal or interstitial cells 

 come to be much more abundant. 



The interpretation put upon such experiments has been that in these 

 cases the specific egg-producing activity of the gonad is no longer utilized 

 but has been supplanted by a reversion to the prepubertal form the form 

 in which the interstitial cells are predominant and that the expression 

 of feminine secondary sex characters in the male host is due primarily to 

 these cells. Further, Steinach and Holzknecht l claim that not only the 

 transplanted ovary but one submitted to the action of x-rays also shows a 

 degeneration of eggs and follicular apparatus and a survival and accentua- 

 tion of the thecal or interstitial cells. 2 When a correct ovarian Rontgen 

 dosage was administered to young females and a considerable time interval 

 allowed to transpire, there resulted a singular and marked mammary en- 

 largement which finally expressed itself in true milk secretion. The 

 ovaries of such animals are said to contain few or no normal follicles or 

 corpora lutea but are full of the same strange hybrid of proliferated thecal 

 and granulosa cells. Here again the pronounced effect of the ovary upon 

 the mammary gland has been referred exclusively to the activities of the 

 so-called interstitial cells. 



It were well to call attention to the fact that in all of the cases which 

 have been cited, i. e., both in normal development and in the experiments 

 which have been detailed, the interstitial cells are not and cannot be 

 clearly separated from the other fundamental ovarian tissue of equal 

 importance the follicular tissue of eggs and granulosa cells. We know 

 that follicular tissue in the adult in its cyclic growth produces very pro- 

 nounced effects (see below) and it would consequently appear unwise to 

 deny it any participation in the function of the ovary before the time of 

 puberty. 3 



Be that as it may, and while one may be in doubt as to the exact 

 proportionate role of the follicular and interstitial tissue, we know that 

 the youthful ovary is responsible for all that important series of physio- 

 logical effects designated as the development of secondary sex characters. 

 The newer experimental work on the ablation of the sex gland in early 



1 So also Hussy and Wallert, Hewer, and Aschner. 



a This had been previously demonstrated by Bouin, Ancel and Villemin. 



'Where interstitial cells are found, follicular tissue has always existed previously. 

 One may also inquire as to the r6le of the egg cells themselves, which Meyer and 

 Schroeder believe to be the real source of control of the cycle in the adult. Meyer 

 has accordingly revised the original sentence of Helmont "Propter solum uterum 

 mulier est quod est" which Virchow had improved by substituting the ovary for the 

 uterus ("Das Weib ist eben Weib durch seine Generations-druse") by now substituting 

 egg for ovary "Propter ovulum mulier est quae est." 



