Dear Sir

I have not at present read or even seen your book on “Worms” but have noticed various reviews. The one in a recent “Athenæum” was most interesting.¹ My present intrusion I hope however will be excusable in what follows.

I have a small patch of ground behind, & have noticed for some years how abundantly supplied it is with “worm life”. It has one feature which perchance has not been possible in your own grounds, as helping to a phase of observation,—e.g. it is surrounded by walls on 3 sides & partly on the 4^th. This ‘enclosure’ of space has rendered one inference of their ways of life a particularly interesting one. It is this—that on a damp evening (let me add that there is a large tree in the enclosure at back which sheds its leaves abundantly, & also has its leaves largely inoculated by the tuberous formation of a certain grub) the activity of the worms on the ground in collecting knots or bunches of leaves together, & in drawing them, burrow-like, into the earth, the noise is such that I have often imagined that a mouse or a cat was jumping & skipping about. In fact such was my first idea, but upon bringing a lighted candle on the scene, I detected that it was merely the noise of the leaves being squeezed into the burrows. The strength & energy exhibited in this drawing in the leaves seemed marvellous. I could not help but conclude that it was the effect of organised aggregation, & that the worms thus indicated the instinct of combined mechanical energy. Some of the bunches of leaves seemed certainly beyond the power of being drawn in by a single worm,—the leaves perhaps numbering from 6 to a dozen, curled up & screwed at the points nearest the worm. They seem to ‘select’ the leaf apex of the leaf to draw in, leaving the stem sticking out of the ground.² They seemed also to become quiescent, or beat a retreat when a light was brought.

The chief point here which I have ventured to name, & which the wall enclosure has been favourable to observing, is—that of the noise & the combined power of organised aggregation which has been evident.

Yesterday being so very wet, & the atmosphere this morning so very humid has partly brought this subject to mind & pen, & must be my apology for intruding these little observings. In fact, on going out into the ground this morning some interesting features seem displayed, & I may venture to enclose ‘specimens’ picked up, & in postscript give the data of such inferences they seem to warrant.

One passage of your work which is noticed by the Athenæum is specially interesting. It is that of the inability of people generally to appreciate the effects of a recurring secondary or subordinate cause.³ When the truth—which you apparently lay stress upon—is more generally ‘credited’, in place of the common notion of separate units of ‘chance’ effects, then the power of truth upon practical life will be more real, & indicate the glories of that unity of Creation which speaks so abundantly of the mystery & marvellousness of the operations of a Divine Spirit, an “Essence” of Life which speaks of God,

With every apology from an ‘Amateur’ observer | I would beg to remain | Yours very faithfully | J. F. Simpson

To D^r C. Darwin F.R.S. | c/o J. Murray Esq

Postscript

1) When the soil is poor, worms seem to abound too greatly, in fact, to over populate the area.

2) They seem to screw up in a ‘spiral’, the inner-cork end of bunches of leaves, drawing the same in, as if by a hook to the bunch,—the aggregated drawing-in seeming simultaneously operating with all the leaves affected.

3) As soon as disturbed, or the outside part of a leaf be touched, they leave go.

4) The excavation of burrow is very clearly done. A twig of a tree descended in a burrowed hole perfectly free for over 3$\frac{1}{2}$ inches this morning, after removing the “cork” of leaves. The clearly formed hole at the ground level also shewed about $\frac{3}{4}$ inch diameter.

5) As they draw in the leaves, they feed off them at same time, particularly seeming to select the tender part, & to eschew the chief woody fibres. (Specimen A)

6) They seem moreoever to shew delicacy of taste in choosing the succulent tuberous grub formations on the leaves, emptying them & leaving the husk remaining. A spider feeds off a fly by exhausting the corpus, but leaves the skin. (I believe this is right—it suggests an analogy between insect & worm instinct.)

(See Specimen B)

7) The leaves fed off by worms seem immaterial,—lilac or other kinds being indifferent.—

(See Specimen C)

8) It may be remarked that there is some thing singularly striking in noticing the rustling noise of the leaves being drawn-in, (as named in letter) when one’s attention is kept constantly attracted almost first on one side, then on another side, the wall enclosure rendering it so very plain in its acoustical sense. | &c

With Compts & apologies,