194 FRUIT CULTURE. 



inserted upon the stock at another period of 

 growth, and in different ways. It may also be 

 regarded as but a modified form of a cutting, 

 inserted upon a stock already provided with 

 roots, instead of inserting into the soil, for the 

 formation of its own roots. Having strong and 

 vigorous stocks it is obvious that speedy results 

 would follow the engrafting of scions* The usual 

 time for the operation is early spring, when 

 both stock and scion are dormant, but about 

 ready to start. Plums and cherries require to 

 be grafted very early, before there are signs of 

 any flow of sap, or swelling of the bud. But 

 provided the scions be kept dormant, apples, 

 pears, and grapes may be grafted much later, 

 even until in full leaf. In a close house, or 

 frame, with moist heat, grafting may be success- 

 fully performed at any season and with partially 

 ripened wood, but in the open air it is necessary 

 that the scion, at least, should be in a dormant 

 condition. There are three conditions essential 

 to successful union, viz. : First, that the inner 

 bark and cambium of the stock and scion come 

 in contact and coincide with each other to some 

 extent ; second, that this union be secured by a 

 firm pressure ; third, that a permanent covering 

 be applied which shall exclude air and moisture. 

 Numerous modes of accomplishing these ends 



