78 VEGETABLE PHYSIOLOGY 



sometimes free, and sometimes disposed in the form of an 

 open network, are surrounded by delicate parenchymatous 

 tissue, whose cells are in immediate contact with the woody 



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

 PARENCHYMA OF A LEAF. 



elements, as they are in the root (tig. 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. TRANSVERSE SECTION OF THE BLADE OF A LEAF, SHOWING 

 THE INTERCELLULAR SPACES OF THE INTERIOR. X 100. 



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

 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 exerting a 

 relatively high osmotic pressure. The woody elements 



