PREFACE. VU 



naturalists will agree with the views I have 

 advanced. 



My thanks are due to the Editors of the Maga- 

 zines and Reviews above mentioned for their 

 courteous permission to republish the articles. 

 I take this opportunity also of expressing my 

 obligations to several friends who have criticised 

 my work, both from the literary and scientific 

 standpoints, and have enabled me to remove not 

 a few serious defects. Especially do I thank Mr 

 S. T. Dadd for the infinite pains he has taken 

 in preparing the illustrations. In almost every 

 instance (and in all where technical accuracy was 

 important) the sketches were made direct from 

 nature, and were submitted to competent authori- 

 ties before they were finally completed. 



Streatham Hill, 

 London, S.W., Oct. 4, 1897. 



