192 BOTANICAL GAZETTE [SEPTEMBER 
Fic. 68. Section of tetrad, showing continuity of exospore around the 
four microspores, and spore mother cell membrane enveloping the tetrad. 
The protoplasm is a thin vesicle with a single nucleus, parietally placed, and 
surrounding a large central vacuole. 
Fic. 69. Exterior view of mature microspore showing pebbled exospore. 
Fic. 70. Vertical section of male gametophyte after first division of spore 
into generative and vegetative cells. 
. Male gametophyte as seen by focusing through spore coats. 
The ee generative nucleus lies near the wall, the vegetative cell not in 
foc 
Bice 72. Male gametophyte showing generative cell in section. 
G. 74. Male gametophyte showing lenticular vegetative cell at left. 
The eas of the content constitutes the generative cell with a centrally 
placed nucleus. Masses of deeply staining proteid matter appearing. 
G. 75. Section of male gametophyte in which masses of proteid matter 
have increased in number. Vegetative cell appressed to wall at left 
1G. 76. The protoplasm is aggregated around the centrally placed 
generative nucleus and has sent out radiating processes, connecting it with 
a peripheral layer. The vacuoles thus isolated are filled with a semi-fluid 
ame matter, 
, 78. A common appearance, where a large symmetrical mass of 
proteid matter (solid black) in the central vacuole may be mistaken for a 
nucleus, 
1G. 79. First division of generative nucleus. Persistent vegetative cell 
appressed to wall in lower portion of figure 
IGS. 80-87. Phases of the early divisions leading to the spermatozoid 
mother cells. 
Figs. 88-95. Sections in various planes showing the two cell complexes 
and their relation to the dissolving proteid masses by which they are envel- 
oped. The masses of food matter are separated by strands of protoplasm in 
Jigs. 88,93, 95 
FiG. 96. Exterior view of male gametophyte displaying trefoil shaped 
cleft in apical portion. The complexes of spermatozoid mother cells protrude 
through the gap. 
FIG. 97. Male gametophyte with spermatozoid mother cells as seen by 
focusing through spore coats. The unusually persistent vegetative cell is 
represented lying above the mother cells. 
F1Gs. 98, 99. Male gametophyte at maturity. The endospore protrudes 
like a short pollen tube through a gap on the ruptured exospore, and contains 
a slimy homogeneous fluid which later is discharged with the spermato 
zoids. 
FIG. 100. A transverse section of a female gametophyte displaying the 
