My dear Sir—

I have read your book on Mould & Earthworms with a wonderful amount of interest—¹ It seems strange that the geological work done by worms should not have been realised before—but so it is with every discovery—so simple when explained!—

My special object in writing is to mention that the blue underclay of the—peat- & forest-bed—shewn in the section in my paper “on the date of the last change of level in Lancashire” (copy of which I sent to you)² is penetrated with rootlets to a depth of full 5 feet—of some plant and that if a clean section is cut horizontally with a knife innumerable tubes are seen generally $\frac{1}{8}$ in diameter & quite circular-hollow, but lined with the skin of the rootlet now quite flabby— In a few cases there are grains of sand in the tubes but generally they are hollow—

There are from 2 to 4 to the square inch— A vertical section cut clean with a knife intersects them at varying angles shewing that they to some extent twist about

—Can any of these be worm burrows into which the rootlets have grown? Between the clay & the peat there is in places mould 6in thick in others hardly any— This mould must have been the work of worms— Unfortunately there are no stones nor the smallest gravel in the clay so we cannot observe the selection of particles— But what becomes of the argillaceous matter where worms burrow in clay? I am now engaged in engineering an outlet sewer 3 miles hence which gives a good section shewing the connection of the Forest Bed with the inland peat and at the point we have arrived now the peat being 5 feet thick there are no rootlets in the underclay the bottom part of the peat being almost entirely composed of water plants—the common flax preponderating—³

Unfortunately I am no botanist & none here seem to take an interest in the question—

What can the rootlets be of?— They are quite distinct from the tree rootlets & fibres—

Yours sincerely | T. Mellard Reade

D^r. Chas. Darwin FRS &c