In April Weather 59 



scales are too small to leave well-defined marks. 

 But in maples and horse-chestnuts the marks 

 of the bud-scales of vanished springs are easily 

 seen. The spaces between them vary from one 

 inch to six or eight, for growth differs in differ- 

 ent years, in different trees, or in different branches 

 of the same tree, according to the humidity and 

 heat of the season, the richness of the soil, or the 

 inherent vigor of the individual. 



At the very heart of each bud which tips a 

 bough or twig is the " apex of growth," a group 

 of generative cells on whose strength and activity 

 the prolongation of the branch depends. The ex- 

 tension of the bough for the season is over and 

 done at a comparatively early period. In many 

 trees it is completed a month after the first little 

 leaves unfold. 



By mid-July even the most procrastinating of 

 trees and shrubs have made the growth of the 

 year, and formed next season's buds. Their sub- 

 sequent efforts are devoted to perfecting and 

 strengthening the young parts, and to laying by a 

 store of nourishment against the needs of another 

 spring. 



A leaf-bud is generally formed just above the 

 foot-stalk of a leaf. On a very young branch the 



