﻿130 THE ENTOMOLOGIST. 



colours. Starting from the first idea, I have been led to others 

 suggesting several lines of investigation which I can fairly claim 

 as my own, — at least in this sense, that I do not owe them to 

 others, although very possibly others may have been led to the 

 same ideas ; with these I hope to deal further on. But this 

 subject itself was first suggested to me by the remark of 

 Wallace's that I have already quoted. I was reading ' Tropical 

 Nature ' some three or four years ago, and, being struck by the 

 statement, made a note of it as a hint for future research. Owing 

 to press of other work, however, my good resolutions were indefi- 

 nitely postponed, and finally slumbered in forgetfulness. Some 

 time since I came upon my old memorandum of the subject, and 

 my attention was redirected thereto. Although still too busy to 

 spare time for the work, I kept it in mind ; and while yet thinking it 

 over, a fresh impetus was indirectly given to my interest in the 

 matter by Mr. Cockerell's article in the ' Entomologist ' of 

 January, 1889. Soon afterwards, before commencing any experi- 

 ments, I wrote out at some length my d priori views on the 

 subject, and the lines of investigation proposed to be followed, as 

 well as the classes of results that I anticipated; from this statement 

 I shall have directly to quote some passages. During the spring 

 I commenced a few preliminary experiments, but want of time 

 prevented me doing much just then; and it was not until 

 September that I was able to settle down into regular work. 

 Since then I have been following up the subject, but lack both of 

 time and opportunity have still conspired to prevent any rapid 

 progress. This may be readily understood when I say that daylight 

 is essential to this work, and the only possible opportunity of 

 daylight working that I have is on Sunday mornings; most of 

 these since August I have given up to the work, and have already 

 got through many hundreds of experiments. 



All of these, however, I regard as merely a preliminary explo- 

 ration. I have now fairly satisfied myself as to the methods and 

 reagents likely to prove serviceable, and am not without hope of 

 soon being in a position to communicate the results of a very 

 extensive series of investigations. So far as I can at present 

 foresee, I anticipate having abundant time and opportunity for 

 this work after next autumn onwards, and nothing will then 

 be wanting me but material in the shape of insects. 



The results already arrived at, although confined entirely 

 to British insects, and therefore covering a very small field, I am, 

 nevertheless, induced to publish without further delay, and that 

 for several reasons. In the first place, they are, so far as they go, 

 fairly complete ; and although — since most of my results are 

 negative — very disappointing compared with my a priori anticipa- 

 tions, yet they may at least guard any future worker from losing 

 time in experimenting with useless reagents or on immovable 

 colours. 



