270 PRACTICAL BOTANY 



described. Passing towards the apex of the bud observe 

 successively earlier stages of their development. 



Examine the sections with a higher power, and 

 observe 



1. The arrangement of the cells at the summit of 

 the apical cone, which is terminated by a single conical 

 apical cell : from this segmental cells are successively 

 cut off. 



2. The origin of the leaves is not from a single cell, 

 but by the outgrowth and subsequent division of a 

 number of cells at the periphery of the apical cone. 



3. Occasionally examples of branching* of the axis 

 will be found, and the lateral branches originate below 

 the actual apex, though above the youngest leaves, by 

 bulging out of a mass of cells : the branching is thus 

 monopodial. 



In such median longitudinal sections the differentia- 

 tion of the vascular bundle from the primary meristem 

 should also be observed, and also the development of the 

 lacunar tissue, and its relation to the central bundle. 



Preparations may also be made of the apex so as to show the 

 structure of the apical cone as seen from above. By comparison 

 of a number of these it may be seen that the form of the apical 

 cell is by no means constant, but varies between the forms of a 

 two-sided and a three-sided cone. If the sections be not suffi- 

 ciently transparent, they may be treated with " eau de javelle " 

 before mounting in glycerine. 



X. Cut longitudinal sections through fertile branches 

 similar to those cut from the vegetative bud, and 

 examine them under a low power. 



Observe that the general arrangement of the stem, 

 leaves, and ligules is the same as in the vegetative 



