i8o INTERNAL SECRETIONS 



of 1000 testicles examined by him he found none which could 

 serve as an example of the wholly normal testicle. Kyrle is 

 of the opinion that most of the new-born have underdeveloped 

 testicles. This is surely an exaggeration. If most of the new- 

 born who die from accidents during birth have testicles of 

 a certain structure, it is most likely that this is the normal state. 

 As to the degenerative changes in the adult testicle which 

 Kyrle so often met, the}^ relate to a very restricted number of 

 tubules. I found the same several times in our "normal'* 

 laboratory rabbits and guinea pigs. It may be that this 

 backward development of seminal tubules, occasionally 

 occurring in normal men and animals, has some Idnd of 

 genetic relation with the cyclic changes which occur regularly 

 in other species. 



Notwithstanding all the contradictory reports related above, 

 it seems that in general there is an atrophy of the seminal 

 tubules, and an increase of the interstitial cells, in serious acute 

 and chronic diseases, and, further, that an atrophy of the 

 interstitial cells may occur when the organism is very much 

 injured by the disease. Two objections must be taken into 

 consideration; first, that the increase is only an apparent one, 

 caused by the degeneration of the tubules, and, secondly, that 

 the increase, if really present, is not caused by a direct influence 

 of toxic substance, but represents only a reaction to the 

 degeneration of the tubules. The first objection, which we have 

 already met with several times in other connections, could be 

 advantageously studied in microscopic detail, and by taking 

 into consideration the total volume of the interstitial cells. 

 Kasai's statement is of importance here ; he sometimes observed 

 mitotic figures, which shows that the increase in the number of 

 cells is not always merely an apparent one. The second 

 objection is of a rather different order. There is no 

 doubt that the increase of the interstitial tissue is in many 

 cases merely a local reaction to changes occurring in the 

 tubules, and may be a process related to the regeneration of the 

 seminal tubules, as was pointed out hy Kyrle (1911). But, on 

 the other hand, certain observations have been made showing 

 that the increase of the interstitial cells can take place inde- 

 pendently of changes in the tubules. An observation of 

 Hedinger (1920) must be mentioned here. He observed a man 

 of 29 with a chorion-epithelioma of the right testicle. The 



