DESCENDING SAP US 



plant, mixes with the substances brought by the 

 ascending sap, and with them becomes the nourish- 

 ing liquid, the descending or elaborated sap, from 

 which all future parts of the plant are to be formed. 

 This liquid cannot be called wood, bark, leaf, flower, 

 or fruit; it is not at all like any of these, and yet 

 it is essentially a little of them all. An animal's 

 blood is neither flesh, bone, nor fleece; but bone, 

 flesh, and fleece are of its substance. Likewise the 

 elaborated sap is -a liquid designed for the sustenance 

 of all parts of the plant ; it contains matter for fruit 

 and wood, leaves and flowers, bark and buds. It is 

 the plant's blood; everything in the plant gets from 

 it its nourishment, its wherewithal to develop. 

 What a wonderful, what an incomprehensible process 

 its production appears to us ! In the crowded ranks 

 of the leaf-cells, where one would suppose every- 

 thing to be at rest, what activity, what transforma- 

 tions beyond the reach of human science! Liquids 

 swell the cells, ooze from one to another, transpire, 

 infiltrate, circulate, exchange their dissolved sub- 

 stances ; vapors are exhaled, gases come, others go ; 

 the sun's light separates what was united, unites 

 what was separated, and the raw materials of the 

 ascending sap combine henceforth with the materials 

 of life. 



"The elaborated sap descends from the leaves to 

 the twigs, from the twigs to the branches, from the 

 branches to the stalk or trunk, and from the latter 

 to the root, distributing itself here and there on itc 

 way. It circulates between the wood and the bark. 



