PREFACE 
HIS simple book consists of six lectures 
which I had the honour and pleasure of 
giving at the Royal Institution in the Christ- 
mas holidays, 1920-1921. The aim of these 
lectures was mainly to help my very alert 
audience to form vivid pictures of the great 
haunts of animal life, and to get glimpses of 
the subtle ways in which living creatures solve 
the problems of particular places. I have 
kept in the printed pages as closely as I could 
to what I said at the time, hoping to secure 
the virtue of simplicity. J think it would be 
very ungracious if I did not use the oppor- 
tunity of this preface to thank Sir James 
Dewar, LL.D., D.Sc., F.R.S., for the great 
kindness that he showed me when I was for 
a delightful fortnight in the service of the 
Royal Institution. TAT. 
