SCROTAL REPLACEMENT OF EXPERIMENTAL 

 CRYPTORCHID TESTES AND THE RE- 

 COVERY OF SPERMATOGENETIC 

 FUNCTION (GUINEA PIG). 1 



CARL R. MOORE, 



HULL ZOOLOGICAL LABORATORY, 

 THE UNIVERSITY OF CHICAGO. 



The experimental work of Griffiths on the dog in 1893 proved 

 that the testis of a normal breeding mammal, replaced in the 

 abdominal cavity by operation, was converted within a few 

 months into a degenerate testis devoid of an active germinal 

 epithelium; the structure of such a testis was very similar to 

 that found in testes congenitally retained in the abdomen. 

 This structural condition, differing from the general opinion 

 held until recently, is not the result of a faulty embryology but 

 the result of an abnormal environment; the structural counter- 

 part of the congenital abdominal testis can be duplicated in a 

 very short time by moving the adult normal testis from the 







scrotum to the abdomen. Griffiths appreciated the fact that 

 the assumption of this abnormal structural character was due 

 to a change of environment, but he was entirely ignorant of the 

 nature of the environmental difference, or the condition that 

 contributed to the typical reaction. 



In a restudy of this problem of experimental cryptorchidism 

 (Moore, '240) and many other aspects of the biology of the testis, 

 we have obtained considerable information concerning the 

 environmental influences and reactions within the mammalian 

 testicle when this environment is modified. Since the literature 

 on the biology of the testis and scrotum has recently been 

 reviewed and discussed (Moore, *26a) only a few points of 

 importance to the present study need here be mentioned (see 

 also Moore, '266, c, d). We have determined that a functional 

 testis removed from the scrotum to the abdomen does not 

 require months to show the destructive influences of the ab- 



1 This investigation has been aided by a grant from the committee on sex 

 research of the National Research Council; grant administered by F. R. Lillie. 



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