BIOLOGY AND STATISTICS 81 



the result of work published by Professor Karl Pearson ; 

 they consist largely in the elaboration of mathematical 

 methods of dealing with statistical problems, and as 

 such it would be inappropriate to give any further 

 account of them here. 



The mention of the word statistics ' at once raises a 

 certain prejudice in the ordinary mind ; in common 

 parlance j the unreliability of arguments based upon 

 statistics is sometimes treated as proverbial, and as 

 used in biology they have, as a matter of fact, one very 

 serious danger at least. Statistics deal with groups 

 and not with individuals, and there is a real difficulty 

 involved in the fact that the average of a group may 

 represent something quite different from any individual 

 which the group contains, whilst at the same time a 

 group may include individuals of very diverse natures. 

 Nevertheless, when used without prejudice to the future 

 examination of individual inheritance by more detailed 

 investigations, the methods of biometry have un- 

 doubtedly yielded information of great value to the 

 evolutionist, particularly in the case of such material 

 as that afforded by the human race, since the applica- 

 tion of precise experiments to this particular species is 

 at present out of the question. 



Some students of biometry, however, would go very 

 much further than this, for it is their professed opinion 

 that their own form of study is the only method by 

 which any real advance in our understanding of the 

 processes of evolution can be brought about.* This 

 opinion is based upon the assumption, of which proof 

 *[ This statement is perhaps no longer true. Ed.] 



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