The subsistence of all organized beings is derived from sources external to themselves; and the sources of their aliment as well as the modes in which these aliments are applied, exhibit an almost endless variety. As might be expected, the widest differences, both in the nature of the alimentary substances, and in the manner of their introduction, are between plants and animals. We shall, therefore, consider the subject of nutrition under these two heads.

SECTION I

Of the Modes of the Nutrition of Plants; and of the Nature of those Matters by which their Nutrition is effected.

A minute investigation of the anatomy and the physiology of plants, would be quite foreign to the object of this treatise. At the same time, it is necessary that the reader should have some insight into these departments of knowledge; in order that he may be enabled to understand the collateral researches, which it is our duty to illustrate.

“If we reflect upon the phenomena of vegetation,” says Professor Lindley, “our minds can scarcely fail to be deeply impressed with admiration at the perfect simplicity, and, at the same time, faultless skill, with which all the machinery is contrived, upon which vegetable life depends.