PREFACE 



It is a Japanese custom to commemorate in some way or other 

 one's sixtieth birthday. 



A few years ago, Mr. Y. Nawa, Director of the Nawa Entomo- 

 logical Laboratory, suggested that, should lie reach the age of sixty, 

 he would be glad to have the happy event commemorated in some fitting 

 way. It was then decided to publish a special volume in commemo- 

 ration of the happy event, and with the approval of many scientists 

 this plan was announced in the March issues of last year of the Zoo- 

 logical Magazine and the Insect World. 



In response to this, many scientists have kindly sent us treatises con- 

 cerning insects and I have been given the honour of editing and pro- 

 ceeding these in the present volume. 



Kikujiro Nagano, 

 Expert of 

 Nawa Entomological Laboratory. 



Gifu, October, 1917. 



