CHAPTER VII. 



THE LEAF TRANSPIRATION LEAF-FALL. 



IT will appear later that the parts of the flower (the 

 petals, stamens, &c.) have the morphological rank of leaves. 

 If these are omitted from consideration, leaves may be 

 classified into (i) foliage-leaves, (ii) scale-leaves. The first 

 are the ordinary leaves familiar to everyone; the other 

 kind of leaf is smaller, dry and hard in texture, colour- 

 less or dingy in tint, devoid of chlorophyll, and pro- 

 tective, not assimilative, in function. Scale-leaves of this 

 sort have already been met with in the potato, the surface 

 of which is marked by the remains of the scales, in 



FIG. 41. 

 HORSE-CHESTNUT BRANCH, bearing a terminal and two axillary buds. 



