INTERNAL SECRETION OF TESTICLE 163 



activity in animals with highly hypertrophied interstitial 

 tissue in transplanted testicles. Similar observations have been 

 recorded by Lacassagne and Sand in animals with ligature of 

 the vasa deferentia. On the contrary Alfred Kohn (19 14 a) 

 points out that in cases of retained testicles there are no such 

 results, notwithstanding the hypertrophy of the interstitial 

 cells. There is a disproportion between virility and inter- 

 stitial tissue. But against all these contradictory statements 

 manifold objections may be made. First of all, in view of my 

 own observations, I cannot but repeat that I have httle con- 

 fidence in quantitative statements concerning sexual activity 

 in rats, guinea pigs and rabbits; secondly, it is still an open 

 question whether there is always in a retained testicle a real 

 hypertrophy of the interstitial cells (the hypertrophy being 

 possibly in many cases only an apparent one); thirdly, 

 the functional state of the interstitial tissue must also be 

 taken into consideration. Fig. 8y {Lipschutz, 1923 a) may 

 serve as an example. Horizontal sections through the testis 

 and the ductus epididyraidis were made on both sides at an 

 age of two months. The animal was observed for about six 

 months. It remained eunuchoid as shown by the observation 

 of the penis. Spermatogenesis had ceased at a somewhat 

 earher stage than in Fig. 66. No differential stain for fat was 

 employed, but the large vacuoles occupying the enormous 

 interstitial cells and separated only by very small threads of 

 protoplasm are most probably remains of droplets of fat. In 

 some places interstitial cells of the usual appearance were 

 present. Were the interstitial cells normal or not, and is the 

 eunuchoidism in this case to be explained by an abnormality 

 of the interstitial cells ? Another case is also of high interest 

 (Lipschutz, 1921c; 1922 d). There was an underdevelopment 

 of sex characters in a guinea pig with a very small upper 

 testicular fragment (Fig. S8) in which quite normal interstitial 

 cells were to be found. It is most probable that there was 

 in this case a retarded development of the testicle and of sex 

 characters, due to the operative interference in the former, 

 and that the animal would have attained some time later full 

 sexual development. But quite apart from all this, the ques- 

 tion remains whether it is justifiable to expect an increased 

 hormonic effect when the interstitial tissue is hypertrophied. 

 By taking into account certain general physiological and 



