BIOLOGY AND STATISTICS 81 
The more recent advances in biometry are mostly 
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, 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 me proof 
