166 GENERAL BOTANY 



ANFRACTUOSUM, whose bare branches sticking out at 

 right angles to the trunk are so familiar a sight in 

 South India. Other common deciduous trees are : 

 BOMBAX MALABARICUM (the Silk-cotton tree), POIN- 



CIANA REGIA (the Gold-mohur), ALBIZZIA LEBBEK, 

 SLEICHERIA TRIJUGA, PLUMERIA (the Pagoda-tree), 

 ODINA WODIER and Teak. In some of these the young 

 leaves are formed within a few days of the fall of 

 the old ones, and in some POINCIANA, PLUMERIA and 

 BOMBAX, the flowers appear before the young leaves; 

 this indeed is very commonly the case. 



The fall of a leaf does not mean a mere tearing 

 away from the branch. In many palms, indeed, the 

 leaf-stalk breaks, and leaves for a while a ragged 

 untidy part on the stem, but with ordinary trees and 

 shrubs, the leaf and stalk fall cleanly away from 

 the branch, and there remains only a perfectly clean 

 scar, the leaf -scar. If one be examined directly 

 after the leaf has fallen, it will be seen to have its 

 own perfect skin, a thin layer of bark. This layer 

 is formed across the petiole before the leaf falls, and 

 gradually cuts the leaf blade off from the sap in 

 the axis. The vessels which conduct the sap are the 

 last to be cut by this layer, and when they are the 

 leaf withers and falls off. So that when the leaf 

 has fallen all the sap which would have gone to the 

 blade, and have evaporated from it into the air, is 

 saved for the plant, while the protective covering 

 of cork which is formed over the scar prevents any 

 further loss. 



It seems indeed as if this were partly at least, 

 the purpose of the annual shedding of the leaves 



