472 Journal of Comparative Neurology and Psychology. 



where x and y are deviations from the means of the two corre- 

 lated characters ; <^i and '^2 are the respective standard deviations ; 

 and S denotes summation. 



The values of the coefficients for the correlation between 

 brain-weight and other characters, together with their probable 



errors are shown in Table III/ 



TABLE III. 

 Brain-weight Correlations. 



'It will be remembered that the limiting values of the coefficient of correla- 

 tion arc o and ± i, o indicating entire absence of correlation between the two 

 variables, and -\- 1 and — I indicating perfect positive and negative correlation 

 respectively- 



