Correlation and Variation in the Toad 



609 



which the coefficients are uniformly as high as here. The relation 

 between the correlation of external and internal characters bears 

 out the general conclusions reached in the discussion regarding 

 their variability. The relative correlation of the brain in man 

 has been mentioned by Pearl ('05), who points out that its corre- 

 lation coefficients are of the same general magnitude as those of 

 visceral characters. It should be noted however that the skull 

 coefficients are of this same magnitude, quite unlike the other 



TABLE XXII 



Coefficients of correlatnu — internal and external characters 



Human — 



Heart and liver 



Heart and spleen 



Heart and kidney 



Brain and various skeletal characters, excluding skull . 



Brain and various skull characters . 



Various skeletal characters, excluding skull, average 



Various skull characters, average 



Toad — • 



Gastrocnemii and liver 



Gastrocnemii and alimentary canal 



Gastrocnemii and ovaries 



Liver and alimentary canal 



Liver and ovaries 



Alimentary canal and ovaries 



Various external characters, average 



Human — - 



Strength of pull and height (Pearson '99) 



Strength of pull and weight (Pearson '99) 



Mental ahihty and various physiological characters (Pearson '06). 



Mental ability and various structural characters (Pearson '06). . . . 



278 

 265 

 400 



17 to .35 

 average = .21 

 36 to .55 

 average = .47 

 70 

 35 



696 



skeletal characters. This indicates that the characteristics of 

 the skull are more dependent upon the brain characters than vice 

 versa. 



The relation between variability and correlation as indicated 

 by these and other data may be mentioned here. We have seen 

 that in the toad conditions of high variability and high corre- 

 lation are associated in the female sex. The same relation has 

 been noted in the male of Eupagurus by Schuster ('03), and among 



