I have been through your book, which has greatly interested me, at a hand-gallop; and I have by no means given it the attention it deserves. But the day after to-morrow I shall be going into a new house here, and it may be some time before I settle down to work in it—so that I prefer to seem hasty, rather than indifferent to your book and still more to your letter.
As to the book, in the first place. The only criticism I have to offer—in the ordinary depreciatory sense of the word—is that pages 128 to 137 seem to me to require reconsideration, partly from a substantial and partly from a tactical point of view. There is much that is disputable on the one hand, and not necessary to your argument on the other.
Otherwise it seems to me that the case could hardly be better stated.
Here are a few notes and queries that have occurred to me.
Page 41. Extinction of Tasmanians—rather due to the British colonist, who was the main agent of their extirpation, I fancy.
Page 67. Birds' sternums are a great deal more than surfaces of origin for the pectoral muscles—e.g. movable lid of respiratory bellows. This not taken into account by Darwin.
Page 85. "Inferiority of senses of Europeans" is, I believe, a pure delusion. Professor Marsh told me of feats of American trappers equal to any savage doings. It is a question of attention. Consider wool-sorters, tea-tasters, shepherds who know every sheep personally, etc. etc.
Page 85. I do not understand about the infant's sole; since all men become bipeds, all must exert pressure on sole. There is no disuse.
Page 88. Has not "muscardine" been substituted for "pebrine"? I have always considered this a very striking case. Here is apparent inheritance of a diseased state through the mother only, quite inexplicable till Pasteur discovered the rationale.
Page 155. Have you considered that State Socialism (for which I have little enough love) may be a product of Natural Selection? The societies of Bees and Ants exhibit socialism in excelsis.
The unlucky substitution of "survival of fittest" for "natural selection" has done much harm in consequence of the ambiguity of "fittest"—which many take to mean "best" or "highest"—whereas natural selection may work towards degradation: vide epizoa.