282 



NUMERICAL LAW OF REGRESSION 



f 







2 



L = 



58 

 49 

 59 



whence 



C= 4.75 

 e= 1.9 

 / = 48.9 



In both cases, the regression due to intrapuberal castration began 

 immediately after castration, as in normal subjects. Furthermore, 

 although the mass of tissue before regression was much smaller, the 

 decline began with the same rapidity as in adults: the diminution in 

 length of the comb was 7 mm. (Experiment 7) and 8 mm. (Experiment 

 8) during the 1st week. That the length attained at the end of regres- 

 sion was much less than in the preceding cases is explained by the 

 fact that the comb of a castrated fowl of the same age has not yet 

 attained its final length. As to the duration of regression, it is much 

 shorter than in the preceding experiments, now that the constant C 

 is much smaller, 



SUMMARY. 



The discrepancy in the relative variation of C and of 6 led us to 

 examine more closely the velocity of regression at the beginning in 

 all the cases. At a given point of the curve, the velocity is furnished 

 by the differential quotient of the length with reference to the time: 



dL 



V = — = - ce + a 



dl 



At the beginning of regression, that is to say, at the time 



vo= -C9 



We have tabulated the corresponding numerical values in the various 

 instances: 



