Dear Sir

Your letter is very kind in acknowledging my little “worm” observations.¹ I hesitate somewhat at your quoting me as a worthy authority for an assertion which under your name will go forth so widely. The fact however is a most patent one & certainly I leave it to you to use as you wish, & if you do wish to honour your Amateur correspondent’s name as authority, please do so as modestly as possible.² I might not be so sensitive on this point, if some other of my speculations on certain phenomena in other ways were seeming to commend themselves, but one’s humble observations may yet be true & yet fail of just that sufficiency of evidence which would enable to float them off, & from one ego, to thus tend to influence the mental differentiation & selection of other egos.

On one point of your note let me add, that if worms do not work in concert of mechanical energy instinct they then (the only alternative I can make out) exhibit the the domestic aggregation instinct strongly, under which the “head” of the family pulls in a sufficiency of leaves to feed the burrow inhabitants, & hence, judging from the large bunches of leaves drawn in, that the “ablebodied” worm must be a relatively powerful fellow.³

That there are other interested members of the family waiting for food, I deemed proved a week or two back upon digging up some earth in connection with these drawn-in bunches of leaves, for, within the pod of earth at the base of the leaves, there was invariably quite a community of younger worms.

If, as you think, there is no evidence of concerted energy, I cannot quite account for only a single leaf perhaps being drawn in at one place, whereas a dozen are found screwed into a burrow in another place. Also, the quickness with which they seem to eat away the leaf seems to show that there is more than a single worm at work. True, I have no doubt that only one worm comes out & gathers the surface leaves, but in guaging the apparent clear diameter of the burrow, 3 inches down (about), it shows a wider excavation or periphery than the mere circumference of the body of a single worm would warrant. It is very interesting to notice the stalwart fellow who comes “on search” to the surface, raising his head, & then lowering himself to the surface, he sweeps round the immediate locality in a wide radius which is not ungraceful in movement.

As to the rustling of the leaves, it is really that of their angular impingings against each other in order to be squeezed into the hole. This really bespeaks much required power. We know of ourselves that a considerable amount of muscle-contraction is needed when we even crumple up a sheet of paper in our hands. Under my original surprise at the noise thus made by the worms operations I was in time, when bringing a light (i.e. a steady light, not a match, for the noise of striking a light is a disturbant) to see the leaves moving in being drawn in, apparently so automatically.

I beg to apologise sending all my little observings, but, dear Sir, Believe me | yours sincerely | J. F. Simpson

D^r. C Darwin FRS.

P.S. | I judge that they overpopulate the ground when poor from this fact; i.e. that 3 or 4 years I have tried to grow from seed (not sods) a patch of grass that would last through the winter. Almost every year, the local gardener has said I should succeed with ‘this’ crop, & this ‘crop’, but not so. And this year it is the same. The little patch of ground is now thoro’ly honeycombed on the surface by worm ‘upheavals’ & ‘castings’. The disproportion of grass to the thick seed sowing has been evident. I can only surmise that part of the seeds gets carried down below, & that the little rootlings get torn by the worm burrowings crossing their paths, & also (as cold weather at once shrivels up the residue of grass tufts) that the innumerable worm channels perforating the upper surface, lets in too much cold air to whatever roots had promised to “survive”, & hence their decay & death &c.

I hope I may say that I shall not fail, I think, to be greatly interested in your book, as soon as time &c, enables me to study it &c.

J.F.S.