Page:The American Cyclopædia (1879) Volume VIII.djvu/148

 GRAFTING being formed, is called the cambium layer. It is this which, if a cut be made in a tree, sends out a new growth to close over and repair the wound ; and it is upon the extraordinary vital- ity of this rumhium that the success of grafting depends. The mechanical operations of graft- ing are various, but they all have for their ob- ject the bringing of the newly forming wood and bark of the scion into the closest possible contact with those of the stock. As a general rule, grafting is most successful when the scions are quite dormant, but the forces of vegetation in the stock are active. Fruit-tree scions are cut at any time after the fall of the leaf be- fore the buds begin to swell, and kept in damp sand or saw dust to prevent drying. Cleft grafting is in this country the most common and likewise the most clumsy method, and yet very often the most successful. It is practised upon stocks from an inch to several inches in diameter. The branches of old trees are re- newed by this method, the grafts being inserted in the branches. Sometimes the entire tree of four or five inches diameter is cut to a bare stock and used in the same manner. The stock, whether trunk or branch, is cut over horizon- tally with a sharp saw, and the surface pared smooth with a knife ; a cleft about two inches deep is made in the stock with a grafting knife and mallet ; the scion to be grafted is prepared by sloping its lower end in the form of a wedge about an inch and a half long, leaving it a little thicker on the outer edge. The cleft being kept open with a wedge, the scion is carefully 1. Cleft Gratting. I. The Deration with the stock cut horizontally. 2. With a sloping cat. viv<l with a mixture of loam and cow dung, or with grafting wax, to exclude the air and to facilitate the union. Until a few years ago clay and loam were ex- clusively used, but grafting wax is neater and more effective. Various compositions are in use ; they consist of resin and wax melted to- FIG. 2. Whip Grafting, showing the tongues prepared and after- ward bound together. FIG. 8. -Whip Grafting on the Collar. gether, with lard or linseed oil, and should be of such consistency as to remain plastic in cool weather, yet not run in hot weather. It is best applied by means of strips of well worn muslin or calico saturated with the composition. For root grafts, well waxed cotton twine, or paper waxed on one side, may be used. Where the stock is large two scions are put in on opposite sides, but with small stocks only one is used, and the stock at the side opposite to the scion is cut in a sloping manner to facilitate healing. Another process, called whip or tongue grafting, is considered the most expeditious. The stock upon which it is performed must be slender, from the size of a goose quill to any diameter which coincides with the thickness of the graft. Some smooth, clear part of the stock being se- lected, it is sloped on one side with a knife to a very acute angle. A scion having two or more buds, and of the size to match the stock, is cut with a slope to correspond with that upon the stock ; then upon each slope or cut surface is cut a tongue ; the scion and stock are locked together by means of these tongues in a manner that will be understood by an ex- amination of the engraving. The barks of both being made to correspond, a piece of waxed cloth or waxed twine is wound round them to hold them in place. After the graft pushes its buds, the binding should be loosened and finally removed, when the adhesion is completed. This method is used in root grafting, and may be practised also on flowering shrubs. In saddle grafting, the scion is cleft instead of the stock ; the stock is pared away on each side to an acute angle, so as to allow the scion to sit or ride