16 



THE ART OP 



rough, work, the edge will soon become blunt, and is easily 

 notched. The saw is sharpened with a file made for the 

 purpose. Delicate tools, and even the secateur, should be 

 sent to the cutler. 



Ligatures. 



Almost all the modes of grafting require a ligature to fasten 

 up separated tissues or raised bark, to tie clefts together, and 

 to keep the graft firmly on the stock. If any considerable 

 interval should be allowed to occur between the insertion of 

 the scion and the application of the ligature, [the action of 

 the atmosphere would not fail to have an injurious effect on 

 the graft. The best ligatures are those which can neither 

 expand nor contract under hygrometric influences, and which 

 possess a certain amount of elasticity permitting them to 

 accommodate themselves to the increasing diameter of the stock 

 without cramping it. The thicker the stock is, the firmer 

 should the ligature be ; for in this case the healing of the 

 wound is naturally more tedious, and everything should be 

 done to accelerate it. In cases of grafting where the bark 

 only has been raised, it is sufficient to bring the cortical layers 

 together, and to tie up the graft without compressing it. The 

 ligature is applied with both hands. It is rolled in a spiral 

 manner around the grafted part, drawing it tight at every turn, 

 especially at the beginning and the end, where it is most liable 

 to become loose. It does not matter whether the turns are 

 made very close to each other or not ; the essential point is 

 that the ligature should keep the graft firm. Should it yield 

 on passing the finger over it, it is not sufficiently tight, and 

 must be done over again. Woollen thread combines all the 

 qualities to be wished for in a good ligature ; it adapts itself to 

 the growth of the tree, and is not affected by moisture, as it has 

 been passed through oil in its manufacture. It is very 

 much used in bud-grafting on small branches and medium- 



