The Growth of Stems 159 



seedlings. Usually this is done at or below the surface of the soil. 

 Both cion and stock are cut obhquely, and each is spHt. The 

 upper half of the oblique end of the cion is pushed into the cleft 

 of the stock and is bound firmly in place with raffia or twine. 

 Again, the success of the graft depends upon the contact between the 

 cambium of the cion and the cambium of the stock. 



In budding, a T-shaped cut is made on the side of the stock, 

 through the cortex, down to the cambium. A bud from a tree 

 of the desired variety, with a small oval piece of wood and bark 

 attached, is slipped down inside the cortex of the stock and tied 

 firmly in place. This places the two cambium layers in contact 

 and the two pieces unite. The stock is then trimmed and the bud 

 develops into a branch. When the branch is well started, the 

 original stem is cut off just above the base of the branch. ^ 



Grafting is commonly done in the spring ; budding, in the early 

 fall. The fruit produced on grafted or budded trees is usually 

 like that of the cion, regardless of the variety of stock. However, 

 there are cases in which the cion is modified by the stock. Dis- 

 cussions of these cases may be found in books on horticulture. 

 Grafting is usually possible only between closely related species 

 of plants. Sometimes, however, plants that are more remotely, 

 related may be grafted on each other, as for example tomato, 

 potato, and nightshade, or the pear, apple, and quince. 



The essential features of budding and grafting are relatively 

 simple, but in practice there are details and refinements which 

 are of the greatest importance. The selection of stock and cion 

 and the best method of operation vary not only with the species 

 but with climate and soil. The best results can be obtained only 

 through profiting by the experience of others and the results 

 attained by scientific experiment.- 



^ In budding some hardwoods like hickory and walnut, better results are ob- 

 tained by cutting about a small patch of the bark and allowing the formation of 

 wound callus about the cut edges. As soon as the callus forms, the patch is 

 removed, and a patch of the same size bearing a bud is fitted accurately into its 

 place. The method is called "patch budding." 



