“This result can be obtained: it is no difficult matter to make the tree lose its tap-root and acquire, not a regular bundle of roots of even length; but a short and much ramified root that possesses the advantages of the bunch of small roots without having its shape. Thus in nurseries where young trees remain for some years before being transplanted, after two years’ growth a spade is passed under the surface of the soil to cut off the main root, which would in time become a deep tap-root. The stump that remains then branches out horizontally without going deeper. Another way is to pave the nursery bed with tiles. The tap-root of the young tree pushes downward until it reaches this barrier, where it is straightway forced to stop growing in depth and compelled to send out lateral branches. “The kind of root we have thus far been talking about is primordial, original; every plant has it on emerging from the seed; it appears as soon as the seed germinates. But many plants have other roots that develop at different points of the stem, replacing the original root when that dies, or at least coming to its aid if it continues to live. They are called adventitious roots, and they play a highly important part, notably in certain horticultural operations such as propagating by slips and layers, which we will talk about later. “Besides these two operations, the object of which is to multiply the plant, it is customary to prompt the growth of adventitious roots either for the purpose of fixing the plant more firmly in the ground or in order to increase its yield. The best way to attain this result is to bank up the earth at the base of the stalk. This process is sometimes called earthing up. The buried portion soon sends out a great number of roots. Indian corn, for example, if left to itself is too poorly rooted to resist wind and rain, which beat it down. In order to give it greater stability the farmer earths up the corn. In the earth banked up at the base of the stalk bundles of adventitious roots form and furnish the plant a firmer support.