PROPAGATION. 105 



take the initiative steps of vegetation, and to effect their 

 union by means of new adventitious cells, before the free 

 flow of sap in the growing season. Budding, on the con- 

 trary, is done in the hight of that season, and toward its 

 close, when the plants are full of well matured and highly 

 organized sap, when the cell circulation is most active, and 

 the union between the parts is much more immediate than 

 in the graft ; were it not so, indeed, the little shield, with 

 its actively evaporating surface of young bark, must cer- 

 tainly perish from exposure to a hot dry atmosphere. The 

 cambium, or gelatinous matter, which is discovered be^ 

 tween the bark and the wood when they are separated, is 

 a mass of organizable cells. Mr. Paxton, using the gar- 

 dener's expression, calls it the " pulp." Budding i's most 

 successfully performed when this matter is abundant, for 

 then the vitality of the tree is in greatest degree of ex- 

 altation. 



The individuality of the bud was sufficiently argued in 

 the first section of this chapter, it need not now be again 

 introduced, except as appropriately to remind us of the 

 fact where the propagation depends upon this circum- 

 stance the future tree must spring from the single bud 

 which is inserted. Mr. A. T. Thomson, in his Lectures on 

 the Elements of Botany, page 396, says : " The individ- 

 uality of buds must have been suspected as early as the 

 discovery of the art of budding, and it is fully proved by 

 the dissection' of plants. * * Budding is founded on 

 the fact, that the bud, which is a branch in embryo, is a 

 distinct individual. It is essential that both the bud and 

 the tree into which it is inserted should not only be anal- 

 ogous in their character, as in grafting with the scion, but 

 3* 



