MALE FEKN. SPOKOPHORE. 197 



the apex. Note the circinate curvature which appears 

 at an early period in their development. 



XII. With a sharp razor, wet with water or with very 

 weak spirit, remove the extreme apex of the punctwm, 

 vegetalionis, taking care to cut accurately in a trans- 

 verse plane : mount first in water, and examine with a 

 low power. If the section be thin enough, it will be 

 seen that a cell of triangular outline occupies the 

 centre of the apical cone, while the cells immediately 

 surrounding it are arranged in more regular order than 

 those at a greater distance. This cell is the Apical 

 cell, and the cells surrounding it have been derived by 

 cell-division from it, and are called therefore the 

 Segmental cells : it may readily be seen that these 

 again undergo subdivision. 



N.B. If the section be not sufficiently transparent, 

 it may be treated with very dilute potash and weak 

 glycerine, which will clarify the tissues, and make the 

 cell-walls more distinct. 



XIII. From the apex of another plant cut median 

 longitudinal sections ; mount first in weak glycerine, 

 and a little very dilute potash may be added if the 

 sections are not transparent enough. 



If any one of the sections has passed through the 

 apical cone, in a median plane, the Apical cell will be 

 seen presenting a wedge-like appearance, and the cells 

 around it will show, in the regularity of their arrange- 

 ment, that they have been derived from segments 

 successively cut off from the apical cell. It may be 

 concluded from the observation of transverse and 

 median longitudinal sections that the form of the 

 apical cell is that of a three-sided pyramid. 



