PROPAGATION BY GRAFTING. 217 



matter contained in the wood to which they adhere, and after- 

 wards by the products of its decay. It is in this way, that the 

 Sugar-cane is propagated, the plants that spring from these 

 cuttings being more vigorous, and coming earlier to maturity, 

 than those raised from seed. This method is often employed by 

 the Gardener ; who sometimes varies it, by not detaching the 

 bud from the parent stock, but by bending a branch into the 

 earth, and letting it be partly supported by the juices of its 

 parent, until it has put forth roots for itself. This is termed, 

 propagating by layers. 



347. But there are many cases, in which it is desirable not 

 to trust to the power which the bud may possess, of forming roots 

 for itself ; and advantage is then taken of the tendency, which the 

 growing parts of plants have, to adhere and become united to 

 each other. Such adhesions not unfrequently take place from 

 natural causes. Thus, if two branches, either of the same or of 

 different trees, be lying across each other, in such a position as 

 to rub against one another when moved by the wind, the bark 

 will be worn off from each, and a fluid will be exuded from the 

 wounds, which will be in time converted into solid tissue. This 

 tissue is capable of conveying sap from one branch to the othe?' ; 

 for a tree that has been thus united (for the sake of experiment) 

 to two others, and has been then cut off from all communication 

 with the soil, has continued to live, without any other supply, 

 than that which it derived through these trees. This natural 

 adhesion of vegetable tissue is well seen in the ivy ; the branches 

 of which often interlace and graft together in various places, 

 until the whole forms a rude network, inclosing the trunk of the 

 tree on which it has climbed. 



348. Now the gardener imitates this process, when he wishes 

 to supply the separated buds of a tree or plant, which he desires 

 to propagate rapidly, with nourishment ready to be elaborated 

 by its leaves. He chooses a stock, or stem deprived of its own 

 buds, and cuts off its top in a sloping direction, so as to expose a 

 large surface of wood and bark. He cuts the lower end of the 

 young branch, termed the graft, in a similar manner, and then 

 fixes them together ; taking especial care that the bark and wood 



