PRUNING THE QUINCE, 69 
pearance and office from the leaves, yet, under some cir- 
cumstances, they all assume the same appearance and 
office. Accepting this idea, we are still unable to ex- 
plain how or whya given course of treatment causes a 
tree to convert a part of its buds into flowers, by furming 
their leaf-scales into calyx, corolla, stamens, and pistils, 
while its other buds become branches clothed with 
nothing but leaves. 
The period of fruitfulness varies in different species of 
plants, and in different varieties of the same species. It 
is often in our power to advance or retard these periods 
by our methods of cultivation. The law as stated by 
Lindley is, ‘* Whatever produces excessive vigor in plants 
is favorable to the formation of leaf-buds, and unfavor- 
able to the production of flower-buds; while, on the 
other hand, such circumstances as tend to diminish lux- 
uriance, and to check rapid vegetation, without affecting 
the health of the individual, are more favorable to the 
production of flower-buds than of leaf-buds.” 
(a.) Root Pruning, if performed at the right time, 
checks too vigorous growth in highly cultivated trees and 
renders them fruitful. How far from the trunk of the 
tree to cut off the roots must be determined by the size 
of the tree. Wm. Saunders recommends from three to 
six feet from the stem, according to the size of the tree, 
and to perform the operation by digging a circular 
trench, so as to cut off all the roots. He says: ‘‘ If done 
in August, the supply of sap will immediately be lessened, 
the wood-maturing principle accelerated, and fruit-buds 
formed. The operation has been performed in spring 
with but little benefit, but if done in the fall can not fail 
in producing the desired results.” F. P. Gasson cuts off 
the roots of a tree four inches in diameter, within two 
feet of the trunk, only leaving a circle of roots four feet 
in diameter ; and this, too, after the leaves have fallen in 
autumn. He fertilizes liberally in the fall with solid 
