PROPAGATION. Seeds are the most general means of propagation, but they do not perpetuate improved varieties, espeeially of fruits; buds do, however. Buds are propagated by budding, grafting, setting slips, euttings, layers, offshoots, suckers, and in some plants, as the strawberry, by natural runners. The bulb is a peculiar bud, which propagates by offsets or buds. Tubers, or rhizomes, are underground stems, as in the potato, dahlia, flag, and they propagate the varieties also. Cuttings are portions of shoots, either of ligneous or herbaceous plants; and they are made of the young shoots with the leaves on, or of the ripened wood either with or without its leaves; and after they have, either in an herba ceous state with the leaves on, or with the wood mature, and with or without leaves, been prop erly prepared and planted, they form roots at their lower extremity, each cutting becoming a perfect plant. In general, cuttings should be taken from those shoots of a plant which are nearest the soil; because, from the moisture and shade there, such shoots are more predisposed to emit roots than those on the upper part of the plant. The young, or last-formed shoots, are to be taken in preference to such as are older, as containing more perfect buds in an undeveloped state, and a bark more easily permeable by roots; and the cutting is to be prepared by cutting its lower extremity across at a joint, the lenticels, or root-buds, being there most abundant. When
the cutting is planted, the principal part of the art consists in packing the earth firm at the lower extremity, so as completely to exclude the air from the wounded section. Cuttings emit roots at this section, either in consequence of the action of the accumulated sap in the cutting, as in the case of the ripened wood in deciduous trees and shrubs; or in consequence of the joint action of the accumulated sap and of the leaves, as in the case of cuttings of soft wood with the leaves on, and in a living state. A few plants are propagated by cuttings of the leaves, the petiole of the leaf being slipped off from the par ent plant, and probably containing the latent embryos of buds. Grafting and budding are processes which have been already explained. Inarching may be described as a species of graft ing, in which the scion is not separated from the parent plant till it has become united with the stock. (See Grafting, Budding, etc.)