PRINCIPLES OF THE GROWTH OF TREES. ^ 



one-year shoot of the cherry, Fig. 4, is mostly supplied with 

 leaf-buds, but the short spurs on the second year's wood, 

 which are but dwarfed branches, are covered with fruit-buds, 

 with only a leaf-bud in the centre. 



It is not, however, always the slowest-growing kinds of 

 fruit-trees that bear soonest. There appears to be a constitu- 

 tional peculiarity, with different sorts, that controls the time 

 of beginning to bear. The Bartlett, Julienne, and Howell 

 pears, vigorous growers, bear much sooner than the Dix and 

 Tyson, which are less vigorous. 



By pruning away a part of the leaf-buds the fruitfulness of a 

 tree may be increased ; and by pruning away the fruit-spurs, 

 bearing may be prevented, and more vigor thrown into the 

 shoots. 



Buds are lateral, when on the side of a shoot ; and terminal, 

 when on the end. Terminal buds are nearly always leaf-buds, 

 and, usually being larger and stronger than others, make 

 stronger shoots. The terminal buds are strongest, as a rule, 

 because their leaves of the previous year were more fully ex- 

 posed to air and light. 



Latent Buds. Only a small proportion of all the buds 

 formed grow the second year; the rest remain dormant or 

 latent for years, and are made to grow and produce shoots 

 only when the others are destroyed. The longer a bud re- 

 mains dormant, the more unlikely it is to grow. It usually 

 dies after two or three years, leaving a ridge or crease on the 

 bark. 



Adventitious Buds are produced by some trees irregularly 

 anywhere on the surface of the wood, especially where it has 

 been mutilated or injured ; and they form on the roots of some 

 trees which are cut or wounded. In these cases such trees 

 may be usually propagated by cuttings of the roots. It is 

 usually from adventitious buds, not from dormant buds, that 

 the shoots arise when a limb is severed. These adventitious 

 buds do not exist in the bark, but are formed for the occasion. 



Leaves. These are commonly made up of two principal 

 parts, viz., the framework, consisting of the leaf-stalk, ribs, 

 and veins, for strengthening the leaf, and supplying it with 

 sap ; and the green pulp, which fills the meshes or interstices. 

 The whole is covered with a thin skin or epidermis. The 



