vi PREFACE 



smooth the path of some who would become ac- 

 quainted with that problem, and desire to use their 

 opportunities of observation, the work that has gone to 

 its making wUl have been well repaid. 



To those who cultivate biological thought from the 

 more philosophical point of view, I venture to hope 

 that what I have written may not be without appeal. 

 At such a time as the present, big with impending 

 changes in the social fabric, few things are more vital 

 than a . clear conception of the scope and workings 

 of natural selection. Little enough is our certain 

 knowledge of these things, and small though the 

 butterfly's contribution may be I trust that it will 

 not pass altogether unregarded. 



In conclusion I wish to offer my sincere thanks to 

 those who have helped me in different ways. More 

 especially are they due to my friends Dr Karl Jordan 

 for the loan of some valuable specimens, and to 

 Mr T. H. Riches for his kindly criticism on reading 

 over the proof-sheets. 



R. C. P. 



February, 1915 



