Summary

Thanks RM for information on case of hexadactyly [see RM’s paper, "Hexadactylism", Land and Water, 11 March 1871, p. 179.

Summary

Discusses the origin and advantages of sexual differentiation in terms of division of labour.

Discusses the origin of the giraffe’s neck and the unsoundness of St G. J. Mivart’s view with respect to it.

Points out an error in Descent.

Summary

Mentions the difficulties in explaining the separation of sexes and Carl Nägeli’s view that the sexes of plants were primordially distinct.

Has been experimenting for five or six years to demonstrate that the benefits of crossing are the same as those derived from a slight change of conditions.

Summary

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

Summary

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.

Summary

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.

Summary

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.

Summary

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.

Summary

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.

Summary

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.

Summary

Gives some information on variation of ocelli between sexes in butterfly species.

Proposes publishing a series of papers on mimicry.

Summary

Thanks RM for note on ocelli.

Summary

Encloses a copy of his paper on mimicry [Proc. Zool. Soc. Lond. (1873): 153–61].

Asks whether large variations are more often limited to one sex than slight ones.

Summary

Thanks RM for his paper on mimicry.

Cannot answer RM’s query because he believes it impossible to define large variations.

Believes monstrosities are generally injurious and are not often, if ever, taken advantage of in nature.