122 CARL R. MOORE. 



ditions. Such tubules are more or less restricted to certain 

 regions of the testis and may be entirely devoid of cells in mitosis 

 or cells that appear to be members of the germinal line. Fig. 4 

 shows a small area from the same microscopic section as that 

 from which Fig. 3 was taken, but from the opposite side of the 

 organ which had formed adhesions with the surrounding tissues; 

 this portion of the testis, therefore, was not located in a suffi- 

 ciently favorable position for resumption of germ cell activity. 

 Here the tubules have not, and probably never would have, 

 developed an active germinal epithelium. One cannot always 

 account for the localized regions of degenerate tubules but these 

 are almost invariably found on the side of the testis where 

 adhesions of the tunica albuginea to surrounding structures have 

 been formed, or on the side where the fat body has closely 

 surrounded the organ. 



These degenerate areas within such a testicle do not interfere 

 with the function of the normal areas. Spermatogenetic activity 

 is continuous in the latter and spermatozoa are differentiated 

 and transported to the epididymis; sections of the latter portion 

 show the tubules filled with spermatozoa. Suspensions of these 

 cells in 0.9 per cent. NaCl at the time of killing the animals 

 revealed the spermatozoa to be as vigorously motile as those 

 obtained from an entirely normal epididymis. 



The difference between an abdominal testis and one replaced 

 in the scrotum for a few months is indeed striking (compare 

 Figs. 2 and 3). The entire development of the active germinal 

 epithelium in the case cited, has followed replacement of the 

 testis in the scrotum within five months. In animals 3 and 4 

 the replaced testis were found to contain quantities of sperma- 

 tozoa three months after scrotal replacement despite the fact 

 that the testis had been confined to the abdomen for a slightly 

 longer period than the one considered in detail above. Develop- 

 ment of the entire germinal line follows, therefore, within three 

 months after scrotal replacement and appears as well established 

 quantitatively as after a period of ten months in the scrotum 

 (animals 9 and 10). 



In the case of animal No. 7 the testis partner to the one replaced 

 in the scrotum remained normal throughout the experiment but 



