Pearl, Conrlation in Brain- Weight. 



473 



It will be seen that a generally low degree of correlation 

 exists between brain-weight and the other characters studied. 

 The coefficients run lower even that those of skull characters 

 (cf. Macdonell :04, Table X) and markedly below those be- 

 tween different characters of the long bones (cf. on this point 

 Lee and Pearson :oi, p. 229). On the other hand the brain- 

 weight correlations give values of the same general order of 

 magnitude as those found by Greenwood (:o4) for various ab- 

 dominal and thoracic viscera. The values of the correlation 

 coefficients for particular cases will be discussed in the sections 

 of the paper which follow. 



5. Brain-zveigJitand Sex. All brain-weight statistics agree 

 in showing that the brain of the male is absolutely heavier than 

 that of the female. I have found the sexual difference in mean 

 brain-weight to be practically the same (taking into account the 

 probable errors) for all the races studied, whether considered 

 absolutely or relatively. The absolute differences (in grams) in 

 the mean brain-weight of the sexes are shown in Table IV. 



TABLE IV. 

 Male mean— Female mean 



Only a part of this sexual difference is to be accounted for 

 by differences in other bodily characters. If we take a group 

 of males and a group of females having the same 



