INTERNAL SECRETION OF TESTICLE i8i 



tumour occupied almost the whole testicle, only a few atrophic 

 tubules and isolated interstitial cells being visible in some 

 sections. The man died some time after the extirpation of the 

 right testicle on account of multiple metastases. The micro- 

 scopic examination of the left testicle was of great interest ; the 

 seminiferous tubules were well developed and in a state of full 

 spermatogenesis, and^ nevertheless, any microscopical prepara- 

 tion, whatever place it was taken from, showed an increase of 

 interstitial cells disposed in large groups or nodules of i to 

 1-5 mm. in diameter between loose connective tissue. To 

 control this statement Hedinger examined the testicles of 

 about 100 men, mostly robust and healthy individuals of 25 to 

 35 years of age, who died of Spanish influenza ; he never found 

 groups of interstitial cells which could in any way be compared 

 with those in the left testicle in the case described above. 

 This shows that an increase of interstitial cells cannot be 

 considered merely as a reaction to local changes in the tubules ; 

 hypertrophy of the interstitial tissue can occur independently 

 of any change in the tubules. That hypertrophy of the 

 interstitial cells, although very often only a local reaction to the 

 degeneration of tubules, is not always so, is rendered probable 

 also by some experiments of our own. Horizontal incisions 

 were made on the testicle of adult guinea pigs without touching 

 the ductus epididymidis ("incomplete testicular section" 

 [Fig. 64, III.]). We observed in most of these cases a degenera- 

 tion of tubules only near the level of the incision ; but I have the 

 impression that some hypertrophy of the interstitial cells 

 occurred, nevertheless, throughout the whole testicle between 

 normal tubules in a state of active spermatogenesis (Fig. 92). 

 We have not yet made a detailed examination of the total 

 volume of the interstitial tissue in these cases . Our experiments 

 with partial castration, as reported above, showed further that 

 not only the tubules, but other local conditions also, such as a 

 rich blood supply, are to be taken into consideration in studying 

 the hypertrophy of the interstitial cells. 



In view of the hypertrophy of the interstitial cells in disease, 

 Alfred Kohn objected that no relation has been observed 

 between virihty and the interstitial cells, as one might expect 

 on our theory. I have already tried to show that an increased 

 quantity of hormone in the blood need not necessarily have an 

 increased hormonic effect. On the other hand, it must not be 



