SCROTAL REPLACEMENT OF CRYPTORCHIU TESTES. 123 



it is not necessary that it should be present for development of 

 the replaced testis. This is well shown in the experiment 

 inasmuch as in animals I, 2, 4, 8, 9, and 10 the normal testis 

 was removed at the time of the second operation, and each of 

 these six animals produced spermatozoa in the testis after 

 replacement in the scrotum. 



Out of the nine cases of scrotal replacement only the testis in 

 animal No. 6 failed to produce spermatozoa. This testis was 

 successfully replaced in the scrotal position, but numerous 

 constricting adhesions had been formed and the testis recovered 

 at the termination of its three months in the scrotum was con- 

 siderably smaller than others residing in the scrotum for a 

 similar period of time after replacement. Sections of this testis 

 showed an entire lack of dividing cells in the seminiferous tubules; 

 all cells present appear of the Sertoli type. It appears that all 

 cells of the germinal line had been removed from the tubules 

 and it is doubtful if this testis would have shown recovery effects 

 if it had been allowed to remain in the animal for a considerably 

 longer period. 



The structure of the tubular portion of the testis in this case 

 is typicakof those cryptorchid testes that have not been opposed 

 by a normal testis. Fig. 5 shows, in comparison with Fig. 2, 

 that the tubules have undergone a change from the embryonic 

 type to a type where apparently only Sertoli cells are present. 

 The tubules are larger in diameter and lack undifferentiated 

 cells, and the intertubular spaces are decidedly different from 

 those of the undeveloped testis; interstitial cells of Leydig are 

 prominent. Just why this testis should have failed to develop 

 normal seminiferous tubules as did the other eight of the experi- 

 ment similarly operated is not known unless it can be attributed 

 to the constricting adhesions that developed about it after 

 scrotal replacement. 



The importance of the scrotum in controlling conditions that 

 are essential for testicular activity can be shown by reference to 

 conditions in which the testis was incompletely restored to the 

 open scrotal pouch. In animal No. I scrotal replacement was 

 incomplete inasmuch as the testis had developed adhesions and 

 was held in a position essentially across the entrance into the 



