Ɛpsilon

To W. B. Carpenter   21 April [1873]1

Down, | Beckenham, Kent.

April 21

My dear Carpenter

I read two days ago your article in the last Contemporary, & I must have the pleasure of expressing my extreme interest & admiration at it. This will cause you no trouble, as this note obviously requires no answer. The case of the 3 species of Protozoon (I forget the name) which apparently select differently sized grains of sand &c is almost the wonderful fact I ever heard of.2 One cannot believe that they have mental power enough to do so, & how any structure or kind of viscidity can lead to this result passes all understanding.—

Your views on the function of the brain are also profoundly interesting, but I know not enough for my opinion to be worth a fraction of a farthing. I was, however, speculating on this subject, when writing on Expression; & came to the conclusion that when we actually tasted & thought of a sour taste, the same or some closely related part of the brain must be affected. Had I then known of your views I shd have omitted the first alternative.3

I thank you heartily for the pleasure derived from your article & remain, yours very sincerely | Ch. Darwin

1
The year is established by the reference to an article in the Contemporary Review (see n. 2, below).
2
In the second instalment of an article ‘On the hereditary transmission of acquired psychical habits’ (Carpenter 1872–3) published in the January, April, and May issues of Contemporary Review, Carpenter described the ability of arenaceous Foraminifera (a large group of unicellular marine micro-organisms that are typically found near the bottom of the sea) to construct multiform tests or casings using quartz grains of various sizes glued together by cellular secretions. Carpenter observed that the selection of different-sized grains of sand by different types of forams might be seen to demonstrate intentionality (Carpenter 1872–3, pp. 784–5). Forams now belong to the order Foraminiferida.
3
See Expression, p. 344. In his discussion of the anatomical relation of the brain and the senses, Carpenter proposed that remembered sensations were not direct reproductions of former sensations since the original state was produced externally while the remembered sensation was produced internally by an idea (see Carpenter 1872–3, pp. 790–3).

Please cite as “DCP-LETT-8869,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-8869