Cato[3000] says, that in addition to the vine, the fig, as well as the olive, the pomegranate, every variety of the apple, the laurel, the plum, the myrtle, the filbert, the nut of Præneste, and the plane, are capable of being propagated by layers.
Layers[3001] are of two kinds; in the one, a branch, while still adhering to the tree, is pressed downwards into a hole that measures four feet every way: at the end of two years it is cut at the part where it curves, and is then transplanted at the expiration of three years more. If it is intended to carry the plant to any distance, it is the best plan to place the layer, directly it is taken up, either in an osier basket or any earthen vessel, for its better security when carried. The other[3002] mode of reproduction by layers is a more costly one, and is effected by summoning forth a root from the trunk of the tree even. For this purpose, earthen vessels or baskets are provided, and are then well packed with earth; through these the extremities of the branches are passed, and by this mode of encouragement a root is obtained growing amid the fruit itself, and at the very summit of the tree; for it is at the summit that this method is generally adopted. In this way has a bold and daring inventiveness produced a new tree aloft and far away from the ground. At the end of two years, in the manner already stated, the layer is cut asunder, and then planted in the ground, basket and all.
The herb savin[3003] is reproduced by layers, as also by slips; it is said, too, that lees of wine or pounded wall-bricks make it thrive wonderfully well. Rosemary[3004] also is reproduced in a similar manner, as also from cuttings of the branches; neither savin nor rosemary having any seed. The rhododendrum[3005] is propagated by layers and from seed.
CHAP. 22. (14.)—GRAFTING: THE FIRST DISCOVERY OF IT.
Nature has also taught us the art of grafting by means of seed. We see a seed swallowed whole by a famished bird; when softened by the natural heat of the crop, it is voided, with the fecundating juices of the dung, upon some soft couch formed by a tree; or else, as is often the case, is carried by the winds to some cleft in the bark of a tree. Hence[3006] it is that we see the cherry growing upon the willow, the plane upon the laurel, the laurel upon the cherry, and fruits of various tints and hues all springing from the same tree at once. It is said, too, that the jack-daw, from its concealment of the seeds of plants in holes which serve as its store-houses, gives rise to a similar result.
CHAP. 23.—INOCULATION OR BUDDING.
In this, too, the art of inoculating[3007] took its rise. By the aid of an instrument similar to a shoe-maker’s paring-knife an eye is opened in a tree by paring away the bark, and another bud is then enclosed in it, that has been previously removed with the same instrument from another tree. This was the ancient mode of inoculation with the fig and the apple. That again, described by Virgil,[3008] requires a slight fissure to be made in the knot of a bud which has burst through the bark, and in this is enclosed a bud taken from another tree. Thus far has Nature been our instructor in these matters.
CHAP. 24.—THE VARIOUS KINDS OF GRAFTING.
A different mode of engrafting, however, has been taught us by chance, another great instructor, and one from whom, perhaps, we have learnt a still greater number of lessons. A careful husbandman,[3009] being desirous, for its better protection, to surround his cottage with a palisade, thrust the stakes into growing ivy, in order to prevent them from rotting. Seized by the tenacious grasp of the still living ivy, the stakes borrowed life from the life of another wood, and it was found that the stock of a tree acted in place of earth.
For this method of grafting the surface is made level with a saw, and the stock carefully smoothed with the pruning-knife. This done, there are two modes of proceeding, the first of which consists in grafting between the bark and the wood. The ancients were fearful at first of cutting into the wood, but afterwards they ventured to pierce it to the very middle, and inserted the graft in the pith, taking care to enclose but one, because the pith, they thought, was unable to receive more. An improved method has, however, in more recent times, allowed of as many as six grafts being inserted, it being considered desirable by additional numbers to make a provision for the contingency of some of them not surviving. With this view, an incision is carefully made in the middle of the stock, a thin wedge being inserted to prevent the sides from closing, until the graft, the end of which is first cut to a point, has been let into the fissure. In doing this many precautions are necessary, and more particularly every care should be taken that the stock is that of a tree suitable for the purpose, and that the graft is taken from one that is proper for grafting. The sap,[3010] too, is variously distributed in the several trees, and does not occupy the same place in all. In the vine and the fig[3011] the middle of the tree is the driest, and it is in the summit that the generative power resides; hence it is, that from the top the grafts are selected. In the olive, again, the sap lies in the middle of the tree, and the grafts are accordingly taken from thence: the upper part being comparatively dry. The graft takes most easily in a tree, the bark of which is of a similar[3012] nature to its own, and which, blossoming at the same time as itself, has an affinity with it in the development of the natural juices. On the other hand, the process of uniting is but slow where the dry is brought in contact with the moist, and the hard bark with the soft.