228 



HARLEY N. GOULD 



TABLE 2 



Specimens removed from large colonies containing females, found to be males, anc 

 replaced in hermit shells in which were from one to four large female Crepidulas 



(females as well as males). Several males were put in each hermit 

 shell as was the case with the controls. The two sets of hermits were 

 then shut up in two crates and sunk in the aquarium. 



After ten days three Crepidulas were taken from each lot and sec- 

 tioned. Specimens 61, 62 and 63 of table 1 were taken from the her- 

 mit shells without female Crepidulas. In two of the three the testis 

 was completely and in the third, partly degenerated. In the controls 

 with females (specimens 64, 65 and 66 of table 2) two were normal 

 males, the third showed no spermatocytes. After thirteen days three 

 more were taken from each lot, and showed a still more marked differ- 

 ence (specimens 67, 68, 69; controls, 70, 71, 72). The external genitalia, 

 as well as the testis, degenerates in the segregated males. Still other 

 samples were taken after eighteen days, and at the end of thirty -four 

 days all those left in each crate which had been males originally, were 

 fixed and sectioned. As the tables show, the males which had been 

 separated from the females suffered regressive changes in the testis 



