THE TRANSPORT OF WATER IN THE PLANT 73 



ments, as they are in the root (fig. 59). These delicate cells 

 are also in contact with the special parenchyma of the leaf, 

 which is in part very loosely arranged and provided with a 

 great development of the intercellular space system (fig. 

 60), which we have seen to be characteristic of the whole 



FIG. 59. ENDING OF A FIBRO-VASCULAR BUNDLE IN THE 

 PARENCHYMA OF A LEAF. 



of the tissue of the plant. The cells abutting on the 

 bundles are filled, like the root-hairs and the cells of the 

 cortex, with a watery sap which contains substances possess- 

 ing a relatively high osmotic equivalent. The woody 



FIG. 60. TRANSVERSE SECTION OF THE BLADE OF A LEAF, SHOWING 

 THE INTERCELLULAR SPACES OF THE INTERIOR, x 100. 



elements of the veins are not completely empty; their 

 walls, at any rate, are saturated with the water ascending 

 from the roots. We have consequently here a resumption 

 of the osmosis which we noticed to play so conspicuous a 



