202 THE Lire HISTORY or 
leaves. In the formation of these organs the upper portion of an 
epidermal cell is cut off by a wall having a horse-shoe shape in 
surface view (/. 7245). The newly formed cell appears to con- 
tain chlorophyl and the nucleus increases in size while the 
protoplasm becomes granular (f. 725c). This mother cell 
divides along a line parallel to the long axis of the epidermal 
cell from which it arose (f. r26e). The later stages of the splitting 
of the wall and the development of the guard cells follows in the 
usual manner (f. 727). The original epidermal cell from which 
the stomatal mother cell was cut off undergoes some alterations 
and it is difficult to distinguish it from its neighbors (f. 121, 122). 
GLanDs. — The glands are club-shaped, measuring about .08 
mm. in length and consist of three cells. These organs originate 
from the upper or apical end of the epidermal cells on both sur- 
faces of the leaves and are inclined toward the apex of the leaf. 
The cross walls become suberized in a few cases and turn a rich 
golden brown (#97, £10; 112, 128). 
SPORANGIA. — The sporangia and the attendant paraphyses are 
borne on the epidermal cells in the bottom of the two grooves on 
the under sides of the sporophyll ) 723, 129). The margin 
of the leaf and the walls of the groove fold over and cover the 
sporangia and form a false indusium. An examination of any 
single sporophyll will show the presence of sporangia in all 
stages of development and these bodies are produced in such 
great profusion that many are not brought to full development. 
The principal features in the development of the sporangia are 
as follows : An epidermal cell sends out a tubular extension 
m which a wall soon appears parallel with the outer wall of 
the epidermis (f. 130 
