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Darwin Correspondence Project

To W. E. Darwin   4 February [1881]

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

Feb. 4th

My dear W.

Many thanks. Do not trouble about Acacia, as yours seems a bad place, & Frank has just collected almost 60 at Mr Teesdale’s place: they also prove ill-adapted for my purpose, as I cannot decide positively, whether basal end, when drawn in, has been gnawed.1 The little leaves sent, were so crumpled, partly from drying that I could make out nothing, & I have got a good body of facts showing that as a general rule leaves are drawn by their apices. Therefore the case of your rhododendron leaves interested me, as 7 were drawn in by base & 2 by apex. The case is all the better in relation to intelligence that the plant is not a native.2 Like a big ass I thought at first that these leaves had been rolled up by the worms, & placed them in water, so that they have expanded somewhat. On reflexion I was almost convinced that they are first rolled up from drying & are afterwards dragged into holes. I find that the shape of the fresh leaves here differs considerably in the different vars., being sometimes much narrower near the base than near apex. I also found many dead leaves somewhat curled up, & I think that in this state their basal end is generally narrower than their apical end, & this wd account for their being generally drawn in by base.

Now will you endeavour to find a good many more drawn-in leaves, & count how many are drawn in by base & how many by apex.— Also look to shape of fresh leaves of neighbouring bushes, & more especially to dead withered leaves & observe whether the curling in is more at base than apex, so that it is best for the worm to drag them in by base.—

I can find as yet here none dragged in.—

I have collected many dead leaves & shall look at them tomorrow & collect still more. But you will see that as the vars. differ I dare not trust to my observations here for the leaves, (perhaps of other vars.) drawn in near you.—

The interest is that worms should apparently be able by touch of ant. end3 of body to judge of shape, so as to draw in objects in the most favourable manner.—

I am now trying triangles of card of this shape,— only 3 as yet have been drawn in & all 3 by apex.—4

diagram

We heard from George this morning just arrived at Madeira after rather stormy passage.—5

Yours affect. | C. Darwin

Footnotes

CD had asked William to observe which end of acacia leaves was drawn into worm burrows (see letter to W. E. Darwin, 31 January [1881]). Francis Darwin had evidently collected leaves at Downe Hall, the home of John Marmaduke Teesdale (Census returns of England and Wales 1881 (The National Archives: Public Record Office RG11/855/92/19)). CD wished to distinguish between leaves used by worms to stop up the mouths of burrows and those that they consumed; he noted that worms often gnawed off small fragments of leaves after softening them with digestive fluid (Earthworms, pp. 57–9).
For the rhododendron leaves and other leaves sent by William, see the letter from W. E. Darwin, 3 February [1881] and nn. 3 and 4.
‘ant. end’: anterior end.
CD gave the results of the ways in which worms pulled triangular pieces of ‘moderately stiff writing-paper’ into their burrows, and the conclusions he drew from these observations, in Earthworms, pp. 82–93.
George Howard Darwin’s letter has not been found. George’s trip to Madeira in 1881 is mentioned in F. Darwin 1916, p. xvi.

Bibliography

Darwin, Francis. 1916. Memoir of Sir George Darwin. In Scientific papers, by George Howard Darwin. Vol. 5. Cambridge: Cambridge University Press.

Earthworms: The formation of vegetable mould through the action of worms: with observations on their habits. By Charles Darwin. London: John Murray. 1881.

Summary

Discusses earthworms and their ability to perceive narrowest points of leaves to draw them into their burrows.

Letter details

Letter no.
DCP-LETT-13036
From
Charles Robert Darwin
To
William Erasmus Darwin
Sent from
Down
Postmark
FE 4 81
Source of text
DAR 210.6: 174
Physical description
ALS 6pp & cov

Please cite as

Darwin Correspondence Project, “Letter no. 13036,” accessed on 28 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-13036.xml

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