Ɛpsilon

To G. J. Romanes   5 February 1880

Down, | Beckenham, Kent. | Railway Station | Orpington.S.E.R.

Feb 5. 80

My dear Romanes

As I feared, I cannot be of the least use to you. I couldn’t venture to say anything about babies without reading my expression book, & paper on infants; or about animals without reading the Descent of man & referring to my notes; & it is a great wrench to my mind to change from one subject to another.1

I will however hazard one or two remarks. Firstly I should have thought that the word ‘love’ (not sexual passion) as shown very low in scale to offspring & apparently to comrades, ought to have come in more prominently in your table than appears to be the case.2

Secondly if you give any instance of the appreciation of different stimulants by plants, there is a much better case than that given by you. Namely that of the glands of Drosera which can be touched roughly 2 or 3 times & do not transmit any effect, but do so if pressed by a weight of 178,000 grain (Insectiv Plants 263). On the other hand the filament of Dionæa may be quietly loaded with a much greater weight with no effect, while a touch by a hair causes the lobes to close instantly.3 This has always seemed to me a marvellous fact.

Thirdly I have been accustomed to look at the coming in of the sense of pleasure & pain as one of the most important steps in the development of mind; & I should think ought to be prominent in your table.4 The sort of progress which I have imagined is that a stimulus produced some effect at the point affected; & that the effect radiated at first in all directions, & then that certain definite advantageous, lines of transmission were acquired, inducing definite reaction in certain lines. Such transmission afterwards became associated in some unknown way with pleasure or pain. These sensations led at first to all sorts of violent action such as the wriggling of a worm, which was of some use. All the organs of sense would be at the same time excited. Afterwards definite lines of action would be found to be the most useful & would be practiced. But it is of no use my giving you my crude notions

Yours very sincerely | Ch. Darwin

The diagram is returned as may wish to show it some one else

LS

1
Romanes’s letter, to which this letter is the second response, has not been found, but Romanes evidently asked CD to comment on a diagram showing the evolution of emotions and intellect in the animal world; the diagram was later published in Mental evolution in animals (G. J. Romanes 1883, facing the title page). For CD’s initial response, see the letter to G. J. Romanes, 3 February 1880 and n. 1. There is a section in the published diagram in G. J. Romanes 1883 that correlates the development of instincts and intellect in different groups of animals with the age at which these faculties develop in a human infant up to the age of 15 months. CD had discussed these topics in Expression, ‘Biographical sketch of an infant’, and Descent.
2
In the published diagram, under the heading ‘Products of emotional development’, Romanes included ‘parental affection’ and ‘social feelings’ at the same level as ‘sexual selection’; the term ‘sexual passion’ does not appear on the chart.
3
Romanes did not include any mention of plants in the diagram. CD had noted that the glands of Drosera rotundifolia (common or round-leaved sundew) did not bend, even when touched with considerable force, if touched momentarily, but bent to the slightest prolonged pressure, while a filament of Dionaea muscipula (Venus fly trap) was highly sensitive to momentary touch but less so to prolonged pressure (Insectivorous plants, pp. 289–90). Romanes discussed the different types of sensitivity displayed by these plants in G. J. Romanes 1883, pp. 49–51.
4
Romanes included a category ‘pleasure and pains’ as a relatively early acquisition under the heading ‘Products of intellectual development’ in his published diagram.

Please cite as “DCP-LETT-12461,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-12461