﻿218 THE ENTOMOLOGIST. 



V. cardtii, V. urticce, Melanargia galatea, Pararge megcera, 

 P. egerides, Epinephele tithonus, E. hyper anthes, Ccenonympha 

 pamphilus, Lyccena artaxerxes, Polyommatus phloeas, Arctia caia, 

 Spilosoma menthastri, A crony eta psi, Triphcena pronuba, Catocala 

 nupta, Moma orion, Agriopis aprilina, Venilia maculata, Abraxas 

 grossulariata, Amphidasys betularia, Larentia fluctuata, Tanagra 

 {Odezia) atrata. 



These, it will be noticed, include representatives of all the 

 great divisions of Macro-Lepidoptera, except the Sphingidse. 



The reagents used were, on the average, 14 or 15 to each 

 insect, making, therefore, a total of nearly 400 experiments on 

 this colour (sic) ; and there is the most complete unanimity possible 

 in the behaviour of black throughout all these divergent families, 

 for in every single instance the result has been nil. In about 

 seventeen instances I have recorded as the result, " little 

 faded," " trifle faded (?)," "browner," &c. ; but practically, and 

 to all intents and purposes, we may say that, so far as these 

 experiments go, black is utterly unassailable by any reagent 

 yet used.* 



2, White. — Species experimented on: — Pieris brassicce, 

 Vanessa atalanta, V. cardui, Limenitis sibylla, Melanargia galatea, 

 Arctia caia, Spilosoma menthastri, Leucoma salicis, Hepialus 

 humidi, Acronycta psi, Catocala nupta, Abraxas grossulariata, 

 Amphidasys betularia, Larentia fluctuata. 



Here, also, are included representatives from each of the main 

 divisions of Macro-Lepidoptera, except the Sphingidse. 



The reagents used were, on an average, 16 to each species, 

 making a total of over 200 experiments on white colouring. The 

 results are almost as perfectly unanimous as those with black, 

 and, similarly, the result was always nil. White is as unalterable 

 as black, and defies equally the action of all my reagents. One 

 honourable and most interesting exception to this otherwise 

 universal sullen indifference must, however, be emphasized, — 

 the white of M. galatea is changed to a deep lemon-yellow by 

 ammonia, and is affected similarly to a greater or less extent by 

 potassic hydrate (sodic hydrate), nitric acid, a little by potassic 

 cyanide, and also by 30 per cent, hydrochloric acid ; but under 

 the influence of this last reagent the yellow was only temporary, 

 as the wing went transparent. No other reagents yellowed it. In 

 a few species with white wings the wing became more or less 



* It may, possibly, cause some surprise that I have said nothing of any attempt 

 at bleaching these colours. As a matter of fact, however, I have— since the first 

 portions of this article were written — tried a few experiments in that direction, 

 using as a bleaching agent hydrogen peroxide, which I thought would be in many 

 ways preferable to chlorine. The results, however, were such as to persuade me 

 that but little was to be gained by the method, and 1 therefore have not referred to 

 it in the text, although contemplating some further experiments therewith before 

 abandoning it for good. 



