Response to ARW’s papers on Papilionidae ["On the phenomena of variation and geographical distribution", Trans. Linn. Soc. Lond. 25 (1866): 1–71; abstract in Reader 3 (1864): 491–3],

and man ["The origin of human races", J. Anthropol. Soc. Lond. 2 (1864): clviii–clxxxvi].

The former is "really admirable" and will be influential.

The idea of the man paper is striking and new. Minor points of difference. Conjectures regarding racial differences; the possible correlation between complexion and constitution. His Query to Army surgeons to determine this point. Offers ARW his notes on man, which CD doubts he will be able to use.

On sexual selection in "our aristocracy"; primogeniture is a scheme for destroying natural selection.

[Letter incorrectly dated March by CD.]