PREFACE TO THE FIRST EDITION 
THE idea of writing this little book occurred to me 
whilst reading Mr. W. C. D. Whetham’s volume on 
‘The Recent Development of Physical Science.’ I 
found the story of the modern progress of physics so 
interesting as to encourage the belief that a similar 
account of the subjects with which I was myself more 
particularly familiar might prove of a like interest to 
other people. I did not, indeed, suppose for a moment 
that I could vie with Mr. Whetham in the power of 
literary expression which renders his book so eminently 
readable. I rather hoped that the peculiar interest 
and importance of the theme might outweigh the 
present author’s deficiencies in this respect. 
For the group of subjects of which I intended to give 
a brief account Mr. W. Bateson has recently proposed 
the term ‘ genetics,’ an expression which sufficiently 
indicates their scope to the initiated. Since, however, 
the meaning of the word ‘genetics’ is not yet clearly 
understood by everybody, it seemed better to adopt 
in the present instance a somewhat more descriptive 
title. 
