CHAPTER III. 



INTERCELLULAR SPACES. 



If the stems of Grasses are cut across, there will be found 

 large cavities extending through whole internodes ; and if 

 thin sections of ordinary leaves are examined under the 

 microscope, there will be seen several lacunae between the 

 cells of the fundamental system. All kinds of the above 

 mentioned lacunae are termed Intercellular Spaces. 



Section I. KINDS OF INTERCELLULAR SPACES. 



Intercellular spaces vary according to their origin and 

 contents, so that they may be classified in two ways. 



1. KINDS OF INTERCELLULAR SPACES ACCORDING 

 TO THEIR ORIGIN. 



Intercellular spaces may be formed either by a splitting 

 of the common wall of adjacent cells as in the leaves of 

 ordinary plants, or by the rupture of certain cells as in the 

 stems of Grasses. 



' / Those formed by a splitting 

 ] of the coininon wall of 



Kinds op intercellular spaces) adjacent cells 



ACCORDING TO THEIR ORIGIN 1 Thoge formed by &e rupture 



I of certain cells. 



2. KINDS OF INTERCELLULAR SPACES ACCORDING TO 

 TSEIR CONTENTS. 



Intercellular spaces contain either air as in the stems of 

 Grasses and ordinary leaves, or certain peculiar substances 



