The Buds. 85 
In the apple and pear, the buds on the so-called fruit- 
spurs are not necessarily flower-buds, but some seasons all 
are leaf-buds. How early in the life of the bud its 
character is fixed, or if flower-buds ever change to 
leaf-buds before expanding, does 
not appear to be known. The fact 
Fie. 36. Fig. 37. Fig. 38. Fig. 39. 
Fig. 36. Flower-buds of Pottawattamie plum, Prunus angustifolia. The cen- 
tral bud of each group is a leaf-bud. 
Fig. 37 Fruiting branch of European plum, Prunus domestica. B, young 
wood. A, wood of preceding year. S, fruit spurs. 
Fig. 38. Fruiting branches of Morello cherry, Prunus cerasus. B, young 
wood. A, wood of preceding year. F, clusters of fruit-buds, 
Fig. 39. Leaf-buds of the apple. 
Fig. 40. Fruit-bud of apple (F). 
All are reduced one-half. (Figs. 37, 38, 39 and 40 are after Barry). 
that leafy shoots sometimes grow out of the center of flow- 
ers, and that petals (143) are sometimes developed as leaves, 
suggestthat such a change may occur. 
134. The Comparative Vigor of Leaf-Buds on a 
given shoot depends upon their location, and the length and 
diameter of the internodes. The terminal bud, when unin- 
jured, is usually the most vigorous one, and the vigor of the 
