[1]1a
From "Von Buch on the Flora of the Canaries".1 "On continents the individuals of one kind of plant disperse themselves very far, and by the difference of stations of nourishment & of soil produce varieties which at such a distance not being crossed by other varieties and so brought back to the primitive type, become at length permanent and distinct species. Then if by chance in other directions they meet with an other variety equally changed in its march, the two are become very distinct species and are no longer susceptible of intermixture".
P.S. "Natural Selection" explains almost everything in Nature, but there is one class of phenomena I cannot bring under it,— the repetition of the forms & colours of animals in distinct groups, but the two always occurring in the same country & generally on the very same spot.2 These are most striking in insects, & I am constantly meeting with fresh instances. Moths resemble butterflies of the same country — Papilios3 in the east resemble Euploeas,4 in America Heliconius.5 At Amboyna6 I took on the same tree at the same time two longicorns7 of distinct genera, but so alike in colour & markings that I only separated them after some days — Here also & at Macassar8 occurs together a Malacoderm9 & an Elater10 of exactly the same tints of metallic blue & soft orange [2] & also similarly striate,— yet there is no affinity between them.10a A few days ago only I took a new & curious little Cicindela11 which so closely resembles in size & markings a Therates12 occurring with it, that I never know which it is till I take it out of my net;— yet there is no sign of a change in the structural characters which separate these genera. It seems to shew that colour, markings & texture of surface depend strictly on local conditions — Home Entomologists might do something in experiments on breeding insects, varying conditions of food[,] light[,] heat[,] &c as much as they will bear. In domestic var[ietie]s. have you discovered what tends to produce white, black, or particular coloured variations? or what tends to produce spots rather than stripes.
ARW. [signature]
13It is like Electric organ in orders of fishes14
Hemp seed on Birds15
Toads — poison on Parrot[']s feather16
Colour correlated with other peculiarities
Status: Edited (but not proofed) transcription [Letter (WCP4079.4026)]
For more information about the transcriptions and metadata, see https://wallaceletters.myspecies.info/content/epsilon
Please cite as “WCP4079,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 7 June 2023, https://epsilon.ac.uk/view/wallace/letters/WCP4079