336 CELLULAR SURFACES 



To all these may be added what has been termed Plug'-r Grafting. 

 According to Thouin this was used by the Komans in grafting their 

 Olives and Vines, and is mentioned by geoponical writers. The opera- 

 tion, which is performed in the spring, is as follows : a shoot of the 

 previous year, having one or two eyes, is taken and shaved into a 

 longish cylindrical form, immediately below the lower eye ; a hole two 

 or three inches deep, and as large as the graft, is then bored in the 

 side of the stock ; the graft is placed in this hole, and driven in until 

 it fits it exactly, leaving no space between itself and the Stock. If this 

 is done, the libers will be in close contact, and the joining of the graft 

 secure. Some years since this method was revived by a M. Yard, and 

 submitted to the examination of a French committee, who endeavoured 

 to ascertain whether the plan was likely to be of any importance. 

 M. Yard said it might be used with advantage ; 1st, in filling up with 

 branches the spaces left in pyramids.; 2nd, in introducing on lateral 

 branches fruit-spurs, if they, and where they, are absent. As to the 

 first of these uses, the committee remarked that the grafts of last spring 

 resemble fruiting branches more than common branches, which they 

 thought was owing to the almost horizontal position of the graft upon 

 the stock, the ascent of the sap of which is consequently obstructed, 

 and they decidedly preferred side-grafting, heel-grafting, or spur- 

 grafting, whenever possible, if the object aimed at is the filling up the 

 spaces left in pyramids. The second advantage attributed to this 

 method the commission thought real and important. The plug-graft is 

 easy of application, requires no ligature, is quickly inserted, and is 

 by no means unsightly. Such advantages the committee thought likely 

 to recommend the plan when the object is to obtain fruit -spurs from 

 branches which have them not. 



In all these methods, and in every other that could be 

 named, it is indispensable that the cellular surfaces should be 

 brought as much as possible into contact ; for the more 

 completely this is accomplished, the more certain is the 

 operation to succeed. It is undoubtedly true, that, as the 

 cellular system of a tree is diffused through its whole diameter, 

 it is impossible to apply a scion to a stock without their 

 cellular systems coming in contact; and, therefore, it may 

 appear indifferent whether bark is applied to bark, and 

 alburnum to alburnum, or whether the bark is adapted to the 

 wood and the latter to the liber. But it is always to be 

 remembered that each of these parts has special modifications 

 of its own, which modifications require contact with parts 



