Discusses Mivart’s reply ["Genesis of species", North Am. Rev. 114 (1872): 451–68] to CW’s review and to Huxley.

Asks whether CD knows anyone to whom he could usefully send a copy of his phyllotaxy paper [Mem. Am. Acad. Arts & Sci. n.s. 9 (1867–73): 379–415].

Delighted to have cloud of darkness removed by CW’s paper on phyllotaxy [Mem. Am. Acad. Arts & Sci. n.s. 9 (1867–73): 379–415].

Has heard that Mivart will answer CW’s pamphlet [Darwinism (1871)].

Sends details of Alexander Dickson’s paper ‘On some abnormal cones of Pinus Pinaster’ (Dickson 1871).

Has replied [in North Am. Rev. 115 (1872): 1–30] to Mivart’s communication to the North American Review [114 (1872): 451–68].

Discusses the degree of fixedness of different characters in organisms.

CW’s article responding to Mivart [see 8351] on the fixity of species is very clear.

On evolution of language, CD doubts W. D. Whitney’s claim that changes are effected by the will of man. Asks CW when a thing may properly be said to be so effected.

Discusses ideas on the development of language; agrees with CD that it is a process governed by unconscious selection; he considers it analogous to unconscious selection of domestic animals by savages. Remarks on the differing views of Max Müller and W. D. Whitney regarding the origin of language and its development. Comments on the extent to which unintentional effects can be ascribed directly to the agency of free intelligent wills.

CD thanks CW for long, interesting letter; hopes the ideas will be worked into an essay some day.

Suggests dates for a proposed visit and gives instructions for reaching Down.

Arranges to visit CD at Down.

Recommends J. C. Houzeau’s Études sur les facultés mentales des animaux [1872].

Was glad to make CW’s acquaintance.

Discusses the mental powers and habits of animals and considers that those of man are not separated from those of animals by any sort of fundamental barrier; the gulf seems formidable only from a self-conscious, human point of view. Man’s important distinction is his greater ability to act and respond independently of external stimuli, in consequence of his internal accumulation of personal experience.