My dear Wallace,--I have read your review with much interest, and I thank you sincerely for the very kind spirit in which it is written. I cannot say that I am convinced by your criticisms.[95] If you have ever actually observed a kitten sucking and pounding with extended toes its mother, and then seen the same kitten when a _little older_ doing the same thing on a soft shawl, and ultimately an old cat (as I have seen), and do not admit that it is identically the same action, I am astonished. With respect to the decapitated frog,[96] I have always heard of Pflüger as a most trustworthy observer. If, indeed, anyone knows a frog's habits so well as to say that it never rubs off a bit of leaf or other object, which may stick to its thigh, in the same manner as it did the acid, your objection would be valid. Some of Flourens' experiments, in which he removed the cerebral hemisphere from a pigeon, indicate that acts _apparently_ performed consciously can be done without consciousness--I presume through the force of habit; in which case it would appear that intellectual power is not brought into play. Several persons have made such suggestions and objections as yours about the hands being held up in astonishment:[97] if there was any straining of the muscles, as with protruded arms under fright, I would agree: as it is I must keep to my old opinion, and I daresay you will say that I am an obstinate old blockhead.--My dear Wallace, yours very sincerely, CH. DARWIN. The book has sold wonderfully; 9,000 copies have now been printed. * * * * * _The Dell, Grays, Essex. Wednesday morning, [November, 1873]._ Dear Darwin,--Yours just received. Pray act exactly as if nothing had been said to me on the subject. I do not particularly _wish_ for the work,[98] as, besides being as you say, tedious work, it involves a considerable amount of responsibility. Still, I am prepared to do any literary work of the kind, as I told Bates some time ago, and that is the reason he wrote to me about it. I certainly think, however, that it would be in many ways more satisfactory to you if your son did it, and I therefore hope he may undertake it. Should he, however, for any reasons, be unable, I am at your service as a _dernier ressort_. In case my meaning is not quite clear, I will _not do it_ unless your son has the offer and declines it.--Believe me, dear Darwin, yours very faithfully, ALFRED B. WALLACE. * * * * * _The Dell, Grays, Essex. November 18, 1873._ Dear Darwin,--I quite understand what you require, and would undertake to do it to the best of my ability. Of course in such work I should not think of offering criticisms of matter.