CASTLE. — INBREEDING, CROSS-BREEDING, AND SELECTION. 781 



diminish size. Yet the effect of this factor is small as compared with 

 the effects of nutrition, for TV 30 and M 31 differ in tibial length by four 

 units, though inbred practically the same amount ; but M was reared 



TABLE XXIV. 



Correlation between Number of Spines in Sex-combs and Lenoth 

 of Tibia, Series N, Generation 30. 



x = spines (sum of both legs). 



A x = 19.38, J = 9.69 

 Ay = 34.80 



ax = 1.684 

 <ry = 2.842 



r = .7075 -J- .0337 



under uniformly good conditions, iV under varying conditions, which 

 finally became intolerable. Again MSI and A 61, which differ by thirty 

 generations in inbredness, but were reared under identical conditions, 

 have an almost identical tibial length. This is exceeded, however, by 



