190 INTERNAL SECRETIONS 



and their protoplasm becomes filled with big granulations 

 staining with osmic acid. Finally the whole cyst is charged 

 with these cells. As was previously observed by Champy, 

 "corpora lutea" of some kind are formed in the testicle. As 

 Aron points out, this glandular paratesticular tissue develops 

 and persists during the whole time of heat, and its regression 

 begins at the same time as regression of the nuptial features 

 sets in. Experiments performed by Aron on this species are of 

 great interest. It has already been shown in the triton that 

 castration leads to rapid disappearance of the nuptial characters. 

 Now Aron succeeded in destroying the glandular paratesticular 

 tissue by galvanocauterization at the beginning of heat. This 

 operation was successful in several cases ; a rapid and complete 

 regression of the nuptial characters followed. The histological 

 examination showed that the spermatic part of the testicle was 

 intact. We see that the latter alone is not sufficient to prevent 

 castration effects from occurring. If only an incomplete 

 destruction of the paratesticular tissue was made, there were no 

 changes in the nuptial characters. 



Objections have been made by Champy to the experiments 

 of Aron. The various papers of Champy (1922) and Aron 

 (1922) may be consulted. 



Lately Kolmer and Koppdnyi (1923 a, 1923 b) have demon- 

 strated that in Pleurodeks Waltli there is a special organ 

 near the testicle consisting almost exclusively of interstitial 

 cells, though islets of generative tissue can be found also in 

 this special organ. It is scarcely possible to sa}^ anything about 

 the physiological bearing of this organ. 



The results obtained by Lauche (1915) in experiments with 

 partial castration on the frog must also be mentioned. A small 

 testicular fragment left in the body hypertrophied and attained 

 the volume of two normal testicles; in reality there was an 

 hypertrophy up to about the volume of one testicle, as the 

 tubules of the regenerated organ were very distended. In other 

 experiments only one testicle was removed; the remaining 

 testicle showed no hypertrophy. Also no signs of hypertrophy 

 occurred when one whole testicle and a fragment of the second 

 testicle were left in the body. We thus see that the case of the 

 frog is very different from that of the mammal, in which there 

 is no hypertrophy of a testicular fragment, but in which an 

 apparent hypertrophy of the remaining testicle after unilateral 



