INTRODUCTION. 



For about 28 years I lived in the Malay archipelago; nine months in 

 Sumatra, five years in the south-western peninsula of Celebes and the rest of 

 the time in Java : from January 1 863 till August of the same year, from 

 May 1864 till May 1869, from May 1879 till July 1888 and from Januar}^ 1889 

 till June 1894. Most of the time that I passed in Java I lived at Batavia, 

 but during the last two years and a half of my stay in that island also 

 partly at Buitenzorg, both places situated in West-Java; some time also at 

 Semarang, at Touban and at Bojonegoro in Central-Java, as well as at Kediri 

 in East-Java, while I also visited for a shorter time other parts of the island, 

 as the mountains of East-Java and frequently the mountains of West-Java. As 

 far as my extensive official duties allowed me, I occupied myself all that time 

 with the study of the fauna of the Lepidoptera in those places ; hunting for, 

 as much as possible myself, and breeding these insects on a large scale where 

 I had settled down, while I sent out people to hunt for butterflies and 

 caterpillars, augmenting my material for study with what they had caught as 

 well as with that which others had the kindness to send me or with what 

 I could obtain by purchase from other collectors of insects. 



Those that 1 collected in Celebes have since been made known in volumes 

 XXI — XXVIII of the Tijdschrift voor Entomologie : in the same journal several 

 pubUcations about the Java Heterocera have appeared in volumes XLIII, XLIV, 

 XLV and XLVII. Since a long time, however, I have also intended to work 

 out my notes about the Java Rhopalocera ; an extensive material, as well 

 as hundreds of figures of early stages made in Java, most of which are still 

 entirely unknown, and thousands of notes about the biology of these animals, 

 are at my disposal for the purpose. 



But the great expense of such a publication has kept me back till 

 now. Even if I confine myself to those figures which cannot be omitted, 



I 



