12 RELATIONSHIPS OF THE COCCACE^E 



sary. When we pass beyond this point, however, statis- 

 tical study is the only instrument which yields reliable 

 results. For the examination of varieties within the 

 species, biometry is indispensable. In the study of the 

 human races for example this method alone has brought 

 order out of chaos. There are tall men in Italy and 

 dark men in Norway; but statistical work (Ripley, 

 1899) has established the existence of three distinct 

 European races — tall, long-headed, blond in Scandinavia; 

 broad-headed in central Europe; short, long-headed, 

 dark along the Mediterranean. The same biometrical 

 methods are laying for the first time a foundation for a 

 real science of mental and social phenomena (Thorndike, 

 1904; Woods, 1906). Wherever varietal differences are 

 to be studied they prove of supreme value. 



In a second way, too, the statistical method throws a 

 flood of light upon the systematic relationships of vari- 

 able organisms. Different racial types show different 

 correlations of characters, as well as different centers of 

 variation for particular characters. We may take an 

 illustration again from anthropology. Tall men may be 

 dark and short men may have light hair. Yet, passing 

 from the individual to the larger group, it is shown 

 clearly by statistical analysis that tall stature and blond- 

 ness characterize one constituent racial European type, 

 short stature and brunetness another. 



The biometrical methods, which have proved so useful 

 in the study of the races of man, promise to be of even 



