Printed, with minor changes: Life and Letters II, 176-77. At beginning of letter is: gives "very hypothetical" doctrine of [Peter Simon] Pallas as it applies to domestic dogs, viz. that present races of domestic dogs were produced by domestication of wolf in one country, of fox in another, etc., and by subsequent crossing; American dogs have descended from three or four "aboriginally distinct" species, and Europeans from several others; "We believe that all canine species have descended from one parent"; unclear whether all or only some differences in present breeds originated since domestication; importance of period of gestation has been exaggerated; races of man a great difficulty; does not believe Pallas's or [Jean Louis Rodolphe] Agassiz's claim that there are several species of man; [Sepoy] mutiny in India "stopped some important enquiries" about man; "I do not attribute much effect to climate &c."; some plants migrated through tropical lowlands during the glacial period; is lame; hopes H[enry] Holland will not review [Origin (1859)] in Q. Rev. because Holland "is so presumptuous & knows so little."
