Russel Wallace : Alfred Russell Wallace (sic)
Alfred R. Wallace.
"In a recent part of my vol. iii. I have figured one of the high Alpine Colorado Erebias, E. Magdalena, found on the extreme summits, among nothing but rocks. I have also succeeded in breeding another of the Alpine Erebias, E. epipsodea, from egg to imago, and have a full set of drawings for plate. Have also had Chionobas chryxus (also Colorado) and imago, and have all the drawings there. Connected with these Alpine species is a matter I talked over with you, and of which I now write. There must be many genera of Satyridæ in which the larvæ are thick-bodied, inert creatures, very much like many of the Noctuidæ. I have twice raised Arge Galatea from egg to imago. This larva is remarkably like a Noctuid in shape, inertness, in the manner it lies on the ground--curled up so that head touches tail, in a ring, or like a d. The pupa is so like a Eudamus, that when I sent one to Mr. Scudder to ask what it was, he replied, 'Some Hesperid probably, very near to E. tityrus.' It is made loose on the ground or [[p. 612]] in the sod, there being no outer case, and no attachment. The usual hooks of the cremaster are not bent, but straight out and few. Now the Erebia epipsodea, and the three Chionobas which have been bred in this country, C. chryxus, semidea, and jutta, are like the A. Galatea in larval habits and appearance, and the pupa is unattached, and has actually no hooks at all. I read in Buckler, that Satyrus Semele actually makes a case underground (like some of the Sphingidæ), and is inside that like a Hesperid. It is to be supposed that many genera of the Satyridæ pupate unattached, or in cocoons. Mr. Scudder says the eggs of Satyridæ are very like the Hesperidæ, and has to admit the resemblances I have spoken of in the other two stages. But he passes over all this as a mere trifle, and insists that 'in the prime features,' as he calls it, of the imago, the Satyridæ 'out-rank all others.' Now what are the 'prime features' he tells about? They are two: one is that the pupa hangs by the tail, and that there is a regular progression from the Hesperid style of attachment through the Papilionidæ, the Lycænidæ and the Satyridæ; and that the flat ventral side of pupæ in what he calls the higher families, the Suspensi, is an evidence that once they or their ancestors were attached by a girdle, like the Papilionidæ. The other is the atrophied condition of the fore-legs, which is more extreme in the Satyridæ than in any other family, and reaches the last degree in Chionobas. He, in his 'Butterflies of New England,' now issuing, puts Chionobas semidea at the head of the North American butterflies, the top rung of the ladder, beyond which we can go no farther! This is what I call your attention to.
"When we used to study 'Euclid,' we sometimes proceeded by an apparently correct mode of demonstration, till we came to 'which is absurd,' and I hold that this conclusion of Mr. Scudder is absurd on its face. Here is a butterfly on the top of the White Mountains of New England. Its species is found nowhere else than in Labrador and in Colorado, in the latter on the loftiest summits. There is no difference between the three butterflies from the three regions, and yet they cannot have had any communication for untold ages. It is considered as a relic of pre-glacial times in the White Mountains. This butterfly lives in a semi-torpid condition through its short season, lies about on the rocks, has but a trifling power of flight, and dodges the high winds in crevices of rocks. To say that an insect which for perhaps 50,000 years has lived this sort of life, and has not changed in all that time, is the most advanced in the scale of North American butterflies, and so of all the world, is absurd and ridiculous! The wonder is that it has not lost the use of its wings. Therefore the argument is wrong somewhere that leads to such a conclusion. If the premisses are allowed to be correct, then the reasoning has a flaw.
"I do not believe there ever was any derivative progression from one family of butterflies to another. And we cannot say that the Papilionidæ are derived from the Hesperidæ (either because of six legs, or the epiphysis, or any other reason), or the Papilionidæ from the Lycænidæ, or the four-legged families from the six-legged. There is not in the rocks a particle of evidence of such a progression, and the whole thing is the merest fancy. Any differences between families are not owing to derivation, but to the development of each independently, like the rays of a fan.
"W. H. Edwards."