xxiii] LIFE IN LONDON 403 



(pp. 384, 385), while extraordinary development of size in 

 Amboyna is referred to at p. 307 of my " Malay Archipelago." 



This brief outline of the paper will, perhaps, enable my 

 readers to understand the intense interest I felt in working 

 out all these strange phenomena, and showing how they 

 could almost all be explained by that law of " Natural 

 Selection " which Darwin had discovered many years before, 

 and which I had also been so fortunate as to hit upon. 



The only other groups of insects upon which I did any 

 systematic work were the families of Pieridae among butter- 

 flies and Cetoniidae among beetles. Of the former family, 

 which contains our common whites, our brimstone and orange 

 tip butterflies, I gave a list of all known from the Indian and 

 Australian regions, describing fifty new species, mostly from 

 my own collection. This paper is in the " Transactions of 

 the Entomological Society for 1867," and is illustrated by four 

 coloured plates. The other paper, which is contained in the 

 same volume, is a catalogue of the Cetoniidae (or Rose- 

 chafers, named after our common species) of the Malay 

 Archipelago, in which I described seventy new species, the 

 majority of which were collected by myself, and it is illus- 

 trated by four coloured plates, beautifully executed by the 

 late Mr. E. W. Robinson, in which thirty-two of the species 

 are figured. These two papers, filling about 200 pages of the 

 society's "Transactions," occupied me for several months, 

 and if I had not had wider and more varied interests- 

 evolution, distribution, physical geography, anthropology, 

 the glacial period, geological time, sociology, and several 

 others — I might have spent the rest of my life upon similar 

 work, for which my own collection afforded ample materials, 

 and thus settled down into a regular " species-monger." For 

 even in this humble occupation there is a great fascination ; 

 constant difficulties are encountered in unravelling the 

 mistakes of previous describers who have had imperfect 

 materials, while the detection of those minute differences, 

 which often serve to distinguish allied species, and the many 

 curious modifications of structure which characterize genera 

 or their subdivisions, become intensely interesting, especially 



