Page:Popular Science Monthly Volume 33.djvu/751

Rh vegetative propagation of a particular species. In the tiger-lily, for example, the tiny bulbels, that spring from the axil of every leaf, fall off when mature, and form distinct or separate plants on the ground beneath. In other instances, suckers, offshoots, or scions are produced, sometimes underground, as in the Jerusalem artichoke, sometimes above, as in the potentillas and hawkweeds, all of which grow out, to all appearance, into plants like the one from which they originally separated themselves. Many plants produce long, creeping branches, which regularly and systematically root at the nodes. The runners of strawberries are a familiar example of this mode of growth; so, in a somewhat different way, are the eyes of potatoes, the small side-bulbs in certain forms of onion, and the long, underground suckers or scions of the twitch or couch-grass.

When we come to look a little closer, however, at the nature of such seeming reproduction, we can see at once that in none of these cases is a new individual—in the truest sense of the word—really produced: all that has been done is to split up the original single organism into a number of colonies, as it were, or component parts, all still retaining the primitive individuality in shape, color, and every other particular. The branch is a branch while it remains on the tree; it is still none the less a branch in all essentials after it has been severed as a cutting, and made to root afresh like a distinct plant, apart from the remainder of the primitive individual to which it belongs. Gardeners and agriculturists are perfectly aware of the truth of this principle, at least as regards its practical aspect, for they take advantage of it freely in the case of varieties which, as they say, "will not come true from seed." A particular potato-plant, let us say, or a particular rose-tree, possesses certain individual points, which render it desirable in cultivation; and, instead of seeding it, by crossing with another individual, and taking their chance among the seedlings (in which the special peculiarities seldom reappear), gardeners prefer to divide and multiply the original individual to the utmost possible extent, so as to make sure of retaining all the strong points of the plant in question, undiluted by crossing. All the Marshal Niels in existence, for example, are, in the last resort, cuttings from a particular, individual French rose-bush; all the British-Queen strawberry-plants are offsets by runners from a single, exceptionally fine-fruiting seedling.

Take an instance which I see before my eyes this very moment as I raise my head from my temporary study-table on a North African hill-side. The date-palms, which form the wealth of the