272 



NUMERICAL LAW OF REGRESSION 



the testicle is just as necessary for the maintenance of these organs as 

 it is for their growth. 



In these experiments on postpuberal castration, the length and 

 width of the comb were measured each week during the period of 



Fig. 1. Head of a normal adult cock (left) and head of a castrated cock (right). 



Fig. 2. Successive aspects of the comb of a cock during regression: (1) at the 

 time of castration; (2) 5 weeks later; (3) 7 weeks later; and (4) at the end of 

 regression. 



regression. The length (Fig. 1) was measured from the anterior 

 extremity (A) to the most distant point of the posterior portion (B) ; 

 the width from the posterior point of origin (C) to the edge of the 

 highest point of the crest (D). In this way the measurements are 



