i84 INTERNAL SECRETIONS 



that of the control animals. It has been ascertained from 

 former experiments (for references see Tsuji's paper) that 

 thjnroidectomy causes degeneration of the generative part of 

 the testicle. No data are given by Tsuji as to the sexual 

 characters of his experimental animals. In fully grown white 

 mice, fed for a long time without any experimental object in 

 view with a uniform diet of oats and bread, we observed great 

 changes in the seminiferous tubules, many of them being in 

 different stages of degeneration; the penis was normally 

 developed. According to Mattill and Carman (1923), even a 

 uniform milk diet can cause in rats degenerative changes in the 

 testicle; desiccated preparations of kidney, spleen, thymus, 

 etc., were unable to prevent these changes. 



The theoretical value of all these observations concerning the 

 behaviour of the testicle under different conditions (disease, 

 intoxication, diet and operative interference), seems to be very 

 small. But every practitioner will agree that these observa- 

 tions are of the greatest practical interest. It is very probable 

 that intoxications are much more commonly the cause of 

 sterihty in man than admitted hitherto. Since degeneration 

 of the seminiferous tubules does not lead to signs of castration, 

 many cases of sterility in man remain undetected without 

 special examination. The practitioner is as a rule disposed to 

 explain the existence of sterility in the wife as due to an 

 abnormality when he hears that the sexual behaviour of the 

 husband is normal. I am of opinion that one of the greatest 

 mistakes a gynsecologist can make is to refrain from repeated 

 examination of the semen of the husband when a woman is 

 supposed to be sterile. Every practitioner will agree that the 

 difficulties in this field of practical medicine are much greater 

 than is publicly admitted. There are cases where intellectual 

 people suffer for many years from not having progeny, and 

 yet are unable to decide upon consulting a doctor. I regard it 

 as absolutely necessary that the general practitioner should 

 be well trained in this matter both in theory and in practice. 

 In many cases of sterility a properly trained medical man is 

 better able to assist his patients by sound advice and simple 

 explanation than, by having recourse to a severe operation on 

 the uterus. And he may be sure that the success and 

 the gratitude he will obtain will often be incomparably 

 greater. 



