1 84 THE PHYSIOLOGY OF PLANTS 



From this point of view budding is the most advantageous 

 of the two operations, as it consists in the insertion of a bud 

 directly upon the cambium ring of the wild stock. To reach 

 this cambial region the bark is slit open by a T-shaped cut, and 

 the bud is placed under the raised lappets of the bark. The bud 

 may be attached either to a shield-shaped mass of bark alone, 

 or there may be some wood adhering on the inner surface 

 of the latter. In that case the operation is spoken of as 

 "budding with wood." 



In the case of budding, the healing process can practically 

 take place at all the points of contact. As the bark of the 

 old stock has been split in the cambial region, the youngest 

 splint-wood remains on the surface of the wood, the youngest 

 bast cells line the lappets of the bark. From both the regions 

 normally new layers of cells will arise, which tend to fill up 

 the interstices between the scion and the stock. Later on the 

 scion itself will take part in the healing process, sending out 

 similar callus like rows of cells from- its inner surface, just as 

 was done from the bast of the wild stock. 



If the bud has some wood attached to it, the healing process 

 can only take place by means of the narrow cambium zone 

 bounding the scion. In this respect budding with wood is 

 less favourable, as the scion offers less surface for fusion of 

 tissues to take place. But this is of little importance in the 

 case of strong wild stock, as it will form healing callus so 

 rapidly that the participation of the scion in this process may 

 be neglected. On the other hand, this method of budding is 

 much more easy in the case of wood from which the bark cannot 

 readily be peeled, and is therefore much more successful at 

 the hands of an unskilled operator. For it often happens in 

 separating the bark from the wood that the fibro-vascular 

 bundles of the bud remain attached to the wood in the form of 

 a small conical protuberance, and the bud is only represented 

 by a hollow cap, which does not grow out even when the bark 

 has united to the stock. 



How rapidly the fusion of tissues takes place in the case 

 of budding can be seen by the changes which soon make them- 

 selves apparent. Already after twelve hours the cut margins 

 of the bark, and the outermost wood cells, show a thickening of 



