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NOTES AND OBSERVATIONS. 



The Melanism Controversy. — Mr. Kane and others appear to 

 attribute melanism to two entirely different causes. Firstly, that in 

 countries with defect 'of sunshine (such as the British Isles) dark 

 coloration would be advantageous, and consequently is fostered by 

 natural selection ; secondly, to adaptive coloration. What I want now 

 to ask is, where do they draw the line between the two ? To illustrate 

 my question I will bring forward two places on the sea-coast (distant 

 about thirty miles from each other), Portland and Bournemouth. The 

 former is one mass of stone ; the latter is heath-land, the soil of the 

 greater part of which is black and wet ; but Bournemouth has a 

 considerably warmer climate, a greater amount of sunshine, less fog, 

 and a much smaller rainfall than Portland ; yet there is a consider- 

 able amount of difference in coloration between certain species of 

 insects found in the two places, those from Portland being invariably 

 the lightest. For instance, Snti/rus semele : the ground colour of the 

 under side is light at Portland, dark at Bournemouth and also at 

 Glanvilles Wootton. Lycmia agon: some females I have from Port- 

 land are of a lighter brown than usual, and are without the orange 

 bands, reminding one of the var. allous of L. medon. Qnophos 

 ohscurata is of a light grey shade at Portland, still lighter on the 

 chalk soil at Lulworth ; of a darker grey shade at Bournemouth, 

 still darker on Parley Heath. Acidalia promutata is much lighter at 

 Portland than at Bournemouth. The following species are much 

 lighter than is usual in Portland, but they do not all occur at Bourne- 

 mouth : — Kpunda lichenea, Aporophyla australis, Heliophobus hispidus, 

 Afjrotis valUgera, Scoparia mercurella, Larentia olivata, and Sericoris 

 cespitana. Fidonia atomaria and Scodiona helgiaria are slightly darker 

 on Parley Heath, about five miles inland, than they are at Bourne- 

 mouth on the coast. Many species of Lepidoptera are darker on the 

 Surrey heaths than they are on the Sussex chalk downs, yet I believe 

 there is no appreciable difference in the rainfall or the annual amount 

 of sunshine. In reference to pale varieties occurring on chalk soils, 

 it may be as well to mention that I once saw a white variety of 

 Lyccena alsus which had been taken by a boy at Winchester ; and that 

 I possess a pale buft'-coloured variety of Argijnnis aglaia with the 

 black spots and markings very faint, taken at Dover by Mr. Leplastrier. 

 The Eev. W. T. Bree, in recording it in the ' Magazine of Natural 

 History ' for 1832, writes : " The specimen reminds one of some plant 

 which, having grown in the dark, has, in consequence, produced its 

 flowers nearly colourless." The yellow varieties of ZyqcBua, I think, 

 may be cited as another instance of occasional pale varieties occurring 

 on chalk soils. Perhaps some of the pale varieties are owing to their 

 emergence during brilliant moonlight. In reference to the latter part 

 of Mr. Kane's paper (Entom. xxvi. pp. 307-311), leaves frozen on to 

 the ice will also absorb the sun's rays, the ice melting beneath and 

 around them. — C. W. Dale ; Manor House, Glanvilles Wootton, 

 Jan. 3rd, 1894. 



Notes on Melanism. — The following instances of melanism, or 

 tendency thereto, have come under my notice at various times during 



