It is a well-known fact, that we are perfectly ignorant of the native sites of nearly all those gramineous plants, distinguished by Linnæus as Cerealia, whose seeds have from the earliest periods of time served for the food of man, such as wheat, rye, barley, rice, maize, oats: perhaps we must except the two last, as the oat was discovered by Bruce growing under the culture of nature alone; and he was too good a botanist to have mistaken the identity of Avena sativa—and Indian corn may have been found. That some of them were produced in these regions first inhabited by mankind, we have every reason to believe, and the warrant of something like obscure tradition; but our ignorance of the first habitats of these plants is the less to be wondered at, when we consider that it is more than probable that culture and the arts of man have so infinitely changed the form, improved the nature, and obscured the original species, that it is no longer traceable in any existent state. There appears to be a permission from Nature to effect certain changes in vegetables, yet she retains an inherent propensity in the plant to revert to its original creation, which is very manifest in this particular race, for the sorts which we now make use of will not endure the thraldom of our perversion without the artifices, the restraints of man, but have a constant tendency to return to some other nature, or to run wild, as we call it. Man bears them with him in all his wanderings, by his treatment they remain obedient to his desires, and are identified with colonization, but as soon as he remits his attentions, the seeds perish in the soil, or their offspring dwindle in the earth, and are lost. Or we may say, that Nature, having created these things, permits him, in the sweat of his brow, to effect an improvement, and consigns the custody of them to his care, satisfied that he will preserve them for his own benefit as long as required; when his occasion for them ceases, or when by sloth he neglects them, they return to their original creation: the earth might be cursed to bring forth thorns and thistles, but an attendant blessing and mercy was reserved of permitting them to be cultivated, producing healthful recreation and grateful food. If these are plants of immemorial antiquity, the potato is yet of comparatively modern introduction, but the original species from whence all our endless varieties have emanated cannot probably now be ascertained, man having, as observed above, almost created an essential article of food; and it is not unimportant to note the great difference that subsists in the component parts of these varieties—for though, in common estimation, a potato may be a potato, yet we find them very differently compounded. The influence of different temperatures and years may cause these proportions to vary, but I give them as observed in 1828.