§ 1. As in our sketch of the structure of mountains it seemed advisable to adopt a classification of their forms, which, though inconsistent with absolute scientific precision, was convenient for order of successive inquiry, and gave useful largeness of view; so, and with yet stronger reason, in glancing at the first laws of vegetable life, it will be best to follow an arrangement easily remembered and broadly true, however incapable of being carried out into entirely consistent detail. I say, “with yet stronger reason,” because more questions are at issue among botanists than among geologists; a greater number of classifications have been suggested for plants than for rocks; nor is it unlikely that those now accepted may be hereafter modified. I take an arrangement, therefore, involving no theory; serviceable enough for all working purposes, and sure to remain thus serviceable, in its rough generality, whatever views may hereafter be developed among botanists.

§ 2. A child's division of plants is into “trees and flowers.” If, however, we were to take him in spring, after he had gathered his lapful of daisies, from the lawn into the orchard, and ask him how he would call those wreaths of richer floret, whose frail petals tossed their foam of promise between him and the sky, he would at once see the need of some intermediate name, and call them, perhaps, “tree-flowers.”