THE PROPAGATION OF PLANTS. 



89 



no avail if contact is made in any other way, as union only occurs when 

 the two layers of new wood or cambium come in absolute contact. 



Grafting (fig. 115) is almost invariably practised in the propa- 

 gation of fruit-trees. In this case a shoot is cut from a tree 

 desired to be multiplied before the leaves appear, and a slanting cut 

 is made with a sharp knife. The tree to be grafted has a similar 

 cut made in the reverse direction. The two cut sur- 

 faces are then brought directly together, so that 

 both of the newly forming woody fibres come in con- 

 tact, when they are retained in their position by a 

 strip of bast mat. In England we then encircle the 

 graft with a lump of clay (fig. 116). On the Continent 

 grafting wax, composed of rosin, pitch, and tallow, is 

 employed : occasionally the graft is protected by a strip 

 of sheet india-rubber, which may eventually supersede 

 the other methods. When we have a tree, the fruit of 

 which is worthless, we put in two or three dozen grafts 

 at once, and, in the space of two or three years, it 

 becomes a bearing tree, giving a totally different 

 produce (fig. 116). Practically every fruit-tree bought 



Fig. Ii6.-Trce covered FlG, 117 "■. i;'?; ^^U: f'G- "8.- Inarching, 



with Grafts. 



at a nursery has been grafted, so that the root and stem below the 

 graft produces a different fruit from the head; and care must be 

 taken that no shoot be allowed to grow below the graft, or we shall 

 get fruit that we do not desire. 



There are other methods of grafting which we do not often employ, 



