Mr. Wallace said that the points mentioned by the author really presented no difficulties whatever to the Darwinian theory. He asked, for instance, why female birds did not sing. Mr. Darwin had himself explained the reason: it was the same as that for which the plumage of the female bird was less beautiful than that of the male. In birds, as in all the lower animals, the female chooses the male; and it is the attractions of the latter that lead to the pairing. This applied both to the voice and the plumage. Another "difficulty" raised by the author had reference to the winged beetles of Madeira. Mr. Darwin's theory was that, as Madeira was a single island in the middle of the Atlantic, subject to violent storms or wind, insects from it once blown out to sea could not get back again. Flying insects would thus be at a disadvantage and might become extinct, while those without wings would survive. But there were some beetles in Madeira which could not get on without flying, as they would lose their means of subsistence. It was a remarkable fact, however, that such insects had longer wings than the corresponding animals in Europe, having gradually acquired increased power to enable them to battle against the wind. This Mr. Darwin illustrates by supposing the case of a ship striking against a rock near land. Persons who could swim well would get to the shore; those who could swim imperfectly would probably be drowned in the attempt, and those who could not swim at all would remain on the wreck, and have a good chance of getting ashore the next day by the boats. Thus the advantage would be to those who could swim well and those who could not swim at all, and, in like manner, to insects that could fly exceedingly well and those that could not fly at all. The author referred to the circumstance of apple-trees differing in different years in the quantity of fruit, and said that this did not depend upon the war of apple-trees with each other. Mr. Wallace said we must go back to the crab-apple for the true cause. There was a war in Nature, a struggle for existence, not only between one crab and another, but between crab-trees and every other kind of tree. All these trees produced millions of seeds every year, but not one seed in a thousand became a tree. Why did one become a tree rather than another? The slightest difference in circumstances connected with growth would affect the life or death of a particular seed. Again, the author maintained that cultivated plants and domesticated plants, when allowed to go wild, returned to the original form; and he cited as an illustration the case of the pansy. Mr. Darwin and other distinguished naturalists denied that assertion; and the author should have given proofs of it, if he desired it to be believed. With regard to the moral bearing of the question as to whether the moral and intellectual faculties could be developed by natural selection, that was a subject on which Mr. Darwin had not given an opinion. He (Mr. Wallace) did not believe that Mr. Darwin's theory would entirely explain those mental phenomena.