CH. I. 



BY THE SURFACE OF THE ROOTS. 



31 



cases accumulation goes on till the Aveiglit of water can 

 bend the leaf to discharge its contents. 



Leaves are not fitted on to each other like tiles or Rain and 



condensa- 



slates on a roof ; and it is impossible that the ivater-shed gj^^JJ^^/^^'' 

 of trees should be outward or from the stem, because ^^^^^^l^^ 

 the continuity of the outward channel is interrupted at 

 the outward end of every individual leaf. But it is by 

 no means impossible that the water-shed should be 

 inward or towards the stem. And this, the very reverse 

 of Eoget's fact, sometimes is the fact. Where leaves 

 incline upward from the twigs, the twigs upward from 

 the branches, and the branches upward from the stem, 

 in rainy or condensing weather almost every drop of 

 water is shed towards and down the stem ; and the 

 stem of a tree stands the model of a river, rich in the 

 supply of water directly as the number and size of its 

 branches. 



This streaming of the stem may be observed in 

 all trees, but differing in quantity as infinitely as the 

 direction of the growth of their branches and twigs may 

 differ. It is most remarkable and most profuse in 

 Lombardy poplars. To tliis day they may be seen 

 deluged in tears for the fate of their rash and hapless 

 brother : 



Quam platanus vino tam gandet popiilus unda.* 



* In reference to Ovid's physiology of the plane, Macrobins 

 writes : ' Is Hortensius platanos suas vino irrigare consuevit : 

 adeo ut in actione quadam, quam habnit cum Cicerone susceptam, 



