dogstail, quaking grass, agrostis, &c., not one species of which was ever sown by us. It appears that the herbage of our poor thin clay-lands is the natural produce of the soil, for every fixed soil will produce something, and would without care always exclude better herbage. Attention and manures, a kind of armed force, would certainly support other vegetation, alien introductions, for a time, but the profit would not always be adequate. In a piece of land of this nature I have suppressed the natural produce, by altering the soil with draining, sheep-feeding, stocking up, and composting: and scabious, carnation grass, mat grass, and their companions, no longer thrive; but if I should remit this treatment, they would again predominate, and constitute the crop. Most counties seem to have some individual or species of wild plants predominating in their soil, which may be scarce, or only locally found in another; this is chiefly manifested in the corn-lands—for aquatic or alpine districts, and some other peculiarities, must form exceptions. This may be in some measure occasioned by treatment or manure, but commonly must be attributed to the chemical composition of the soil, as most plants have organs particularly adapted for imbibing certain substances from the earth, which may be rejected or not sought after by the fibrous or penetrating roots of another. Festuca sylvatica abounds in every soil without an apparent predilection for any one: F. uniglumis, only where it can imbibe marine salt: F. pinnata, is found vegetating upon calcareous soils alone, and I have known it appear immediately as the limestone inclined to the surface, as if all other soils were deficient in the requisite nutriment. Many of the maidenhairs and ferns, pellitory, cotyledon, &c. are attached in the crevices of old walls, seeking as it were for the calcareous nitrate found there, this saltpetre appearing essential to their vigor and health. The predominating plants in some corn-fields are the red-poppy,[7] cherlock (sinapis arvensis), mustard (sin. nigra.), wild oat, cornflower (cyanus); but in some adjoining parish we shall only sparingly find them. With us in our cold clay-lands we find the slender foxtail grass (alopecurus agr.) abounding like a cultivated plant: when growing in clover, or the ray grass, the whole are cut together, and though not a desirable addition, is not essentially injurious; but vegetating in the corn, it is a very pernicious weed, drawing nutriment from the crop, and overpowering it by its more early growth, at times so impoverishing the barley or the oats, as to render them comparatively of little value. The upright brome grass (bromus erectus) is a pest in our grass lands, giving the semblance of a crop in a most unproductive soil; hard and wiry, it possesses no virtue as food, and is useless as a grass: this bromus inclines to the limestone, the lias, or clay-stone, as if alumine