﻿CHEMISTRY OF INSECT COLOURS. 131 



Secondly, since I do not know whether any others might 

 presently take up the inquiry, I — not unnaturally — wished to 

 establish my priority if possible ; and I now appeal to any of my 

 readers who have not yet worked at this, to leave me alone for two 

 or three years to carry on what I have begun. This is univer- 

 sally conceded by the scientific code of honour to every worker 

 on a new line, and I must ask the customary honourable treat- 

 ment of being left to finish my work myself. Of course if any 

 others, as for instance Mr. Cockerell, have already struck out the 

 same line of work as myself, that is quite another thing ; and 

 although I shall, naturally, be disappointed to find myself not 

 alone in the field, yet evidently their right to continue the inves- 

 tigation is every whit as good as mine, and the mere priority of 

 publication does not entitle me to cry " hands off!" In such case 

 we can only continue our collateral investigations in friendly 

 rivalry. But I do emphatically reserve ni} r rights as against any 

 who might have their attention directed to the subject by merely 

 reading this communication. 



And, thirdly, there is a very practical inducement to make 

 known my present results, for I am most anxious to,_ if 

 possible, examine the colour of typical Lepidoptera of all the 

 chief families, and from all parts of the world, so as to arrive 

 at a fairly comprehensive conclusion concerning the chemical 

 and genetic relationships of these colours. It has therefore 

 appeared to me not improbable that many entomologists whose 

 interest in Lepidoptera is not confined to merely collecting 

 them, but who rather regard the study from the scientific stand- 

 point, might feel inclined to assist me by sending material for my 

 investigations. I have myself none but common English species, 

 and therefore all brightly coloured Lepidoptera, whether Euro- 

 pean or tropical, will be most welcome. To obtain the supply 

 that I want from dealers would be practically impossible, and 

 furthermore extremely wasteful ; for working as I do, such very 

 small portions of the wing are used in each experiment, that a single 

 wing of e.g. atalanta size would, if unicolorous, amply suffice for 

 my experiment on that species.* 



Now there must certainly be numbers of entomologists pos- 

 sessing damaged and broken specimens that are useless for their 

 cabinets and exchanging : if they will send me a wing or two each 



* Where the wings are mottled with several colours, of course one wing of this 

 size would not suffice. Any insects thus sent me will need no packing, but may be 

 sent in simply a stout envelope ; since the preservation of the body is unnecessary, 

 the most convenient mode would be to send simply detached wings. To be of real 

 service all should be named, at least so far as regards genera and family, the specific 

 name is of less account ; and I would greatly desire the locality (Asia, Africa, 

 Europe, &c.) to be stated. It must be remembered, however, that a wrong naming 

 will be far worse than none at all ; and in any case of even uncertainty, it will be 

 better to let me take my chance of getting the insects named at the Museum or 

 elsewhere. All such enclosures may be addressed to me at "Eavenshoe," 142, 

 Burnt Ash Hill, London, S.E. 



