6 PRINCIPLES OF THE GROWTH OF TREES. 



branches, and are simple, as in the common thorn; or 

 branched, as in the honey-locust. Ungraf ted pear-trees often 

 present all the intermediate forms between perfect branches 

 and perfect thorns. Prickles grow only from the bark and 

 when the bark is stripped off they are all taken off with it, 

 but thorns remain attached to the wood. 



Buds are of two kinds, leaf and flower. The former grow 

 into branches, the latter produce fruit. To distinguish these 

 buds is of great importance to the cultivator of fruit-trees. 

 Fie \ represents a portion of the branch of a pear-tree; 



b, b, b are flower or fruit- 

 buds on the extremities of 

 short spurs termed fruit- 

 spurs, and c is a leaf-bud on 

 a one-year's shoot. Fig. 4 

 exhibits these two kinds of 

 buds as seen on the cherry, 

 b, b, being the round fruit- 

 buds, and c, c, the sharper 

 leaf-buds. 



Causes of this Difference. 

 When young trees grow 

 rapidly, all their buds are 

 leaf-buds; when they be- 

 come older and grow more 

 slowly, many of them be- 

 come flower or fruit buds. 

 One is the result of rapid and the other of slow growth. Check 

 the growth of a young tree by transplanting it, or by root- 

 pruning, or by neglecting cultivation, or allowing it to grow 

 with grass, and many fruit-buds will be found upon it, and it 

 will bear early. But as the growth is unnaturally enfeebled, 

 the fruit is not always of the best quality. The natui al di- 

 minution of vigor from increased age furnishes better fruit. 

 Fruit-buds are likewise produced by checking the free flow of 

 the sap in grafting on dissimilar stocks ; as, for example, the 

 pear on the quince, producing Iwarf pear-trees. The fruit- 

 spurs shown by b. Fig. 3, are nothing more than short 

 shoots, originally produced from leaf-buds, but which, mak- 

 ing little growth, have become fruit-bearers. The vigorous, 



FIG. 3 . PIG. 4. 



Leaf and Flower Buds. , b. Flower- 

 buds ; c y c t leaf-buds. 



