INTERNAL SECRETION OF TESTICLE 179 



interstitial cells in chronic diseases such as in tuberculosis of 

 the lungs. They record that this hypertrophy may be very 

 marked, the bands of cells of Leydig between the tubules being 

 twice as large as normally ; there are signs of an intense secretory 

 activity in the cells. But, on the other hand, a degeneration 

 or a complete atrophy of the interstitial cells may take place 

 in diseases, especially in cachexia of long duration. The 

 interstitial cells are decreased in number and size, they are 

 filled with pigment, and their edges are serrated. Bouin and 

 Ancel (1905 b) observed also an hypertrophy of the interstitial 

 tissue in cases of experimental infection or great loss of blood 

 experimentally produced, where the hypertrophy occurs after 

 a few days ; in the final stage of a chronic infection or intoxica- 

 tion (general experimental tuberculosis or alcoholic intoxication 

 during several months) an atrophy of the interstitial cells may 

 occur. The same point was observed in the final stage of an 

 acute mortal infection. In opposition to these statements are 

 those of Kasai, who found no changes in the interstitial tissue 

 in pneumonia and acute tuberculosis; in septicaemia and in 

 purulent peritonitis the interstitial cells were sometimes visibly 

 increased in number, whereas in other cases the interstitial 

 tissue showed no abnormality. In chronic diseases of the 

 organs of circulation or bronchi an increase of interstitial cells 

 was observed only exceptionally. In cancer no increase of the 

 interstitial cells was found by Kasai even when the tubules 

 were atrophied. But a marked increase of the interstitial cells 

 was observed by Kasai in seventeen out of twenty-two indi- 

 viduals who died of tuberculosis. The tubules were mostly 

 more or less atrophied. In some cases also the interstitial 

 tissue was in a state of degeneration, the cells having only a 

 little protoplasm ("quiescent interstitial cells," according to 

 Kasai). The question of the behaviour of the human testicle 

 under different pathological conditions has been very carefully 

 studied by Kyrle (1911, 1920), who examined for this purpose 

 more than a thousand testicles. As Kyrle points out, the 

 testicle in man is sensitive to such a degree that it is hardly 

 ever possible to find a normal testicle in adults who died of 

 acute infectious diseases, such as pneumonia, or acute septic 

 infection. But sometimes the number of tubules affected by 

 degeneration is very restricted. More pronounced are the 

 degenerative changes in chronic diseases. Kyrle says that out 



