FATE OF GERMINAL EPITHELIUM. 149 



viability and a tendency toward clumping. Spermatozoa were 

 found alive in the ductus epididymis, and the vas for nine days 

 after elevation of the entire testis to the abdominal cavity, and 

 since it is reasonably certain that spermatogenic activity ceases 

 on elevation of the organ, and since the spermatozoa pent up in 

 the vas and epididymis were in these locations some time previous 

 to operation, it follows that the length of life of a fully mature 

 spermatozoon is something more than nine days. Just how 

 long a spermatozoon remains in the seminiferous tubule after 

 maturity, and what time is required for its passage into the 

 vas is a question which must be answered before we can state 

 anything more definite concerning the length of life of fully 

 developed sperm. 



As to the role played by the vascular changes in the degener- 

 ative process it must be admitted that insufficient work has been 

 done in this direction to permit of any definite statements. 

 However, from the meager data here presented it would appear 

 that haemostasis induced by ligation of the blood supply to the 

 testis produces a coagulation necrosis of the germinal epithelium, 

 not followed by a removal of the germinal epithelium at least 

 within sixteen days. Hence we are lead to believe that the 

 vascular changes seen in artifically cryptorchid testes is a case 

 of active hyperemia, and that through this agency the degener- 

 ating elements are rapidly taken into the blood stream. 



F. SUMMARY AND CONCLUSIONS. 



1. When the testes of sexually mature male guinea pigs are 

 elevated to and allowed to remain in the abdominal cavity, a 

 progressive desquamation and degeneration of the germinal 

 epithelium takes place; at six days abdominal retention degener- 

 ation is well marked, at ten days well advanced, and at twenty 

 days practically all epithelium has been removed. This degener- 

 ation can be directly attributed to the increased temperature 

 of the abdominal cavity over that of the scrotum. 



2. Neither the speed nor the nature of the degenerative process 

 is effected by ligation of the ductus deferens of the cryptorchid 

 testis. 



3. All of the degenerating elements from the seminiferous 



