Since writing my chapter on worms, I am indebted to the courtesy of the author, for the paper read by Charles Darwin, Esq., before the Geological Society, and published in their Transactions for 1837, p. 505.¹ Its perusal has scarcely modified the views I have already expressed, but it reveals a marvellous coincidence, inasmuch as this careful observer notices the two other modes of elevation of surface adverted to in my chapter, and dismisses them as inefficient, while he clearly and emphatically credits the worms with the whole of the work. And yet it would appear, from pages 506 and 507, that the soil found above the marl, &c., was not of the same quality as that found below it. I presume Mr. Darwin would attribute the difference to the fact of the earth having passed through the stomachs of the worms. In fact, this is obviously his theory, for he adds, that the surface soil would be more properly called animal than vegetable mould.² I, however, would accept the fact of the difference in quality as a strong proof that the bottom soil had not been brought up by the worms, but brought down rather by the plants. The greater part of it has an atmospheric origin. Plants incarnate the sun himself in a visible body; this body is nurtured and sustained mainly by invisible food, produced by the atmosphere, and when it perishes part of it goes back to the air; but a large portion of it is spread out over the surface of the earth in the form of vegetable mould. And doubtless in this emptying of the invisible air down, as it were, in a solid mass of decomposing carbon annually, and hourly, in fact, over the surface of the world, through the instrumentality of every living plant, we have agents of sufficient energy, force, and persistency to cover the earth with vegetable mould without the assistance of manure. The amount of carbon utilised and converted from gases into solids in a single year is well nigh incalculable, and would account for all the elevations of surface so graphically described in the admirable paper of Mr. Darwin. It would be gratifying to many of your readers to know if this distinguished geologist still adheres to his original estimate of the usefulness and power of worms as earth-lifters and surface-elevators. Of this he may be assured, that I had no idea of running counter to any theory of so eminent and careful a naturalist when I began my chapter on worms. Even now I would gladly retreat, if I could consistently with the two rules that I have laid down for myself as a writer:—Is it true? then it ought to be spoken. Is it right? then it ought to be done. But what will Mrs. Grundy say?³ Well, what matters? No great man will ever respect a little one the less for speaking his mind freely, even though it may be in opposition to him. And truth has been said by some to have fallen from heaven down into the gutter, and the humblest—those closest to the gutter—sometimes find it first. D. T. Fish.