Discusses his paper on mimicry and natural selection [Land and Water 9 (1871): 321]. Believes natural selection tends to fix mimetic characters rigidly.

Discusses the problems of mimicry as related to natural selection; the general variability of colour as a character; and the conditions necessary for natural selection to fix firmly a character.

Encloses a Fritz Müller letter speculating that organisms respond to certain colours because of the prevalence of those colours in their environment.

Discusses the roles of natural and sexual selection in producing mimicry, and the problem of explaining the cause of the first mimetic variation; considers the ideas of A. R. Wallace and Fritz Müller on this problem.

Invites RM to keep some specimens as long as he wishes.

Recalls vaguely the mention of a butterfly species in which the male alone is mimetic.

Wishes to use some of Fritz Müller’s observations in his paper on mimicry.

CD’s reply and Huxley’s article ["Mr Darwin’s critics", Contemp. Rev. 18 (1871): 443–76] have answered all of Mivart’s objections to natural selection as applied to man.

A. G. Butler has named the specimens sent by CD with Fritz Müller’s letter.

Sends several facts relating to sexual selection, mimicry, and hybrids.

Discusses the possibility that mimicked and mimicking forms have descended from originally allied forms and have diverged in structure but not in appearance.

Feels it would be worth while but difficult to investigate mimicked and mimicking forms for structural similarities that would indicate a closer alliance in the past.