266 



REPRODUCTION 



together are comparatively large, a good union is very readily 

 made. 



In the process of grafting a short piece of a shoot with from 

 two to four buds upon it is united with the stock. 



In the grafting of fruit trees the grafts or scions are cut in 

 January or February before vegetative growth commences, from 

 well-ripened shoots of the preceding year's growth. They are 

 then placed in moist sand or garden soil on the north side of a 

 waU, or kept in a cool cellar in order 

 to prevent them from drying up and 

 to keep them dormant until they are 

 needed in March or April when the 

 actual operation of grafting is generally 

 carried out. 



The upper part or ' head ' of the tree 

 or stock is cut off completely at a 

 point a little way above where the 

 scion is to be grafted. This prepara- 

 tion of the stock must be done before 

 growth begins in spring, the best time 

 being usually in the early part of 

 February. 



Ver)' numerous methods of uniting 

 the scion to the stock are practised by 

 gardeners and nurserymen. 



In all cases it is important to re- 

 member that the callus or healing- 

 tissue which brings about the union, 

 arises chiefly from the cambium of the scion and stock and the 

 cells immediately bordering on the cambium : the old matured 

 portion of the wood takes no part in the process. 



The commonest modes in use are tongue- or whip-grafting 

 and rind- or crown-grafting, the former being largely adopted 

 where the scion and stock are approximately the same in thick- 



FiG. 95. — Diagram illus- 

 trating mode of tongue-graft- 

 ing. I. Slock a and scion b 

 separate. II. The same fitted 

 together before being bound 

 and waxed. 



