A, PEZARD 



277 



Experiment 4. — Cock, FaveroUe, hatched July 1, 1913, began to display the 

 secondary sex characters in Nov., notwithstanding an attempt at castration 

 later recognized as incomplete. Two testicular nodules about the size of a hazel- 

 nut were extirpated Feb. 26, 1914; regression began immediately; we shall con- 

 sider it as ending at 6 weeks (Fig. 6). Coincidence was not so good as in the other 

 cases, for reasons which we are not in a position to explain at present; it should 

 be added that during the 3 months following (May to July) regression continued 

 but was negligible, being only 3 mm. 



90 



85 



6 

 6 80 



o 

 o 



«♦— 

 o 



'an 

 a 



^ 65 



75 



70 



60 



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 Time in weeks 



Fig. 5. 



Experiment 5. — Cock, Bare-neck, hatched July, 1912. Castrated Nov. 11, 

 1912. Received in right peritoneal cavity fragments of ovary from a pullet of the 

 same brood. These fragments did not appear at once to have any influence 

 on the regression of the comb, which was effected at the normal rate. On the 

 other hand, a small testicular nodule developed after the operation, and from the 

 7th week the phenomenon was reversed and a new growth of the comb brought 

 about, hence the second branch of the curve. At autopsy this nodule was extir- 

 pated: the weight was 1.3 gm. It had the usual testicular structure. Although 

 the two segments of the curve do not appear to correspond, the regression was 

 complete (Fig. 7). 



