GRAFTING. 



227 



GRAFTING. 



linden tree this liber is present in con- 

 siderable quantities, and supplies the 

 material for mats which we call bast, and 

 useful for tying up plants. Within this 

 third bark, intervening between it and 

 the woody stem, is another layer of muci- 

 laginous, viscid matter, called the cam- 

 bium, more abundant and more active in 

 spring than at any other time. It is un- 

 certain whether this belongs properly to 

 the stem or the bark. It is certain, how- 

 ever, that it is a connecting link between 

 them, that both bark and stem are in- 

 creased from it, and that it plays a most 

 important part in the plant as a living, 

 organised structure. 



Cambium. To all appearance the cam- 

 bium is the chief means by which the 

 growth and increase of the tree is main- 

 tained, the organ from which the growth 

 and increase of the tree proceeds. In 

 grafting and budding, it is absolutely 

 necessary that contact be effected behve.en 

 the cambium of the stock and the cambium 

 of the scion. If this be secured, the well- 

 being and junction of scion to stock is 

 certain ; if not, the graft will fail. Hence 

 it appears ho\v necessary it is that this 

 should be known to and recognised and 

 understood by those who attempt grafting 

 and budding. It is to insure a good con- 

 tact between the cambium of the bark that 

 contains the bud and the cambium of the 

 stock that the old wood taken away with 

 the bud is removed before the latter is 

 applied to the stock, and it is because the 

 contact of cambium of scion and stock is 

 rendered more complete in budding than 

 it is in grafting that the former operation 

 is performed more frequently with success 

 by amateurs than the latter. 



Gardening ingenuity has invented many 

 kinds of grafting, but it will be sufficient, 

 in separate articles to follow, to describe 

 a few only of these processes, in order to 

 explain their principle. The first thing to 



be done is to select a suitable stock, whose 

 height will be according to the purpose for 

 which it is intended, and also a graft, 

 which should be from an early branch of 

 the previous year's wood which has ripened 

 under an August sun, so that the wood has 

 been thoroughly constituted before the 

 early frosts sets in. It should also be 

 selected so that the graft is in the same 

 state of vegetation with the intended stock. 

 Where the texture of the wood is less 

 advanced in the graft than in the stock, 

 the latter intercepts the descent of the 

 pulpy sap, and forms the bulging on the 

 stem which is observable on many trees 

 that have been subjected to the process 

 of grafting. When the case is reversed, 

 the swelling occurs in the branch above 

 the graft ; for the principle of the union is 

 that the pulp from the scion descends to 

 the point of junction, where, being shut in 

 by the ball of grafting wax, which sur- 

 rounds it, and thereby secluded from the 

 light and air, it forms woody fibre in place 

 of the roots which it would have formed in 

 the soil ; in the meanwhile, the sap from 

 the stock rises into the graft, where it is 

 elaborated into pulp by the action of the 

 leaves, and returns again, but in a more 

 consistent state. In the preceding re- 

 marks the rationale of grafting is briefly 

 but clearly dealt with. 



Grafting, Cleft or Tongue. 



In this mode of grafting, the crown of the 

 stock is cut across, and a longitudinal wedge- 

 shaped slit, c, as in Fig. i, is made about 

 4 inches long, according to the size and 

 vigour of the intended graft ; this cleft is 

 kept open by a wooden wedge until the 

 scion is prepared. The scion is tlien 

 selected, having a bud, A, at its summit ; 

 and the lower part of it is shaped with the 

 knife so as to fit the slit in the stock. The 

 double-tongued graft only differs from the 

 first in having two grafts in place of one, 



