The peach may be worked upon the plum stock, and is claimed to be somewhat dwarfed by it, and to produce superior fruit. This stock is more congenial to the apricot, which is frequently propagated upon it. Both plums and apricots may be worked upon the peach stock, and they will grow very vigorously, as they will upon the wild plum, but they soon over-grow, and are very apt to break off. When either of these species is used as a stock for the plum or apricot, they should be considered merely as a nursing mother, like the apple or thorn to the pear, which may be wanted to help the cutting until it shall be prepared to stand alone, and feed itself from its own roots. In other words, they should be grafted, _not budded_, into these uncongenial stocks, and the operation should be performed in the collar or below it, in the root, so that the growing scion may be earthed up, and encouraged to furnish itself with a good system of roots of its own. The success will then depend upon the ability of the scion to emit roots freely. We must never forget that in grafting, we are confined to very narrow limits. Our scion must be of a similar nature with the stock, each must have cells of a similar character, capable of transmitting their nutritious fluids from one to the other. We must recollect likewise, that the parts must be so co-apted that the cells of wood growth shall be brought into as close connection as possible, in both scion and stock; these cells are found in the layer, called the cambium, which is between the wood and the bark. The crude sap from below will often pass from cell to cell, when the elaborated sap of the cells in the scion is wholly unfitted for the formation of wood cells in the stock below it; of course the union in such a case must be very imperfect, and the product of such a grafting will be subject to accident, and will be short-lived, though the result in fruit, while the union continues, may be very precocious, abundant, and of superior flavor. Natural grafting may often be observed by the student of nature when wandering among his favorites of the sylvan shades. There can be no doubt that the first hint was thus communicated to the early gardeners. In nature we always find the grafting to be inarching, or grafting by approach; two limbs or even two trees approximating closely, have abraded one another, and have afterward united their tissues most firmly together. This is generally a union of two trees of the same variety or species; but such is not always the case; sometimes trees of very dissimilar natures unite in this manner, but when we examine them we find only a dove-tailing, only a mechanical union, but no vital action subsists between them. The ancients give us some fancy sketches of the unions by grafting of very dissimilar trees, and some moderns who have no higher claim to poetry than their romancing, tell us that we may graft the peach upon the Willow and Buttonwood, and form other equally impossible unions.