I ATE OF GERMINAL EPITHELIUM. 133 



due in all probability to the smaller caliber of the tubules, and 

 a concentration of these cells, and they appear here as a simple 

 epithelial lining for the tubules. With the exception of a few 

 spermatogonia situated near the periphery of the tubules, intact 

 germinal epithelium is practically absent. A few cells of de- 

 generating germinal epithelium are seen free in the lumen; the 

 rete tubules also contain some degenerating material that is 

 being transported to the epididymis as will be pointed out below. 

 The intertubular spaces show slight evidences of vascular stasis; 

 the interstitial cells show no obvious change. The tunica 

 vaginalis is somewhat thickened. 



Thus by the end of the sixteenth day of abdominal retention, 

 practically all of the former conspicuous germinal epithelium 

 has been removed from seminiferous tubules, leaving chiefly a 

 lining of Sertoli cells. 



Twenty-day Cry ptor chid Testes. The testis confined to the 

 abdomen for twenty days is smaller than the preceding organ, 

 and measures slightly more than half the diameter of the un- 

 operated testis in the same animal. The germinal epithelium 

 is still more reduced here, so that only an occasional spermato- 

 gonium may be identified. In about half of the tubules the 

 lumen is distinctly widened at the expense of the Sertoli cell 

 cytoplasm, so that the lumen occupies from one half to two 

 thirds the diameter of the tubule. The interstitial cells are 

 slightly more conspicuous here and the intertubular spaces 

 contain considerable serous exudate. 



We see therefore that by the end of the twentieth day the 

 process of evacuation of the germinal elements is complete, with 

 the exception of a few spermatogonia, which retain their normal 

 position between the bases of the Sertoli cells. 



Abdominal Retention for Longer Periods. Despite the fact 

 that my interest has been primarily in the direction of the 

 disposition of the degenerating epithelium, and that by the end 

 of the twentieth day of abdominal retention practically all of 

 this has been transported from the body of the testis, it has 

 been found necessary to study the epididymis after longer 

 retention. A word or two in reference to the seminiferous 

 tubules of these testes, retained for from twenty-five to one 

 hundred thirteen days, will not be out of order. 



