“Gli * poem 
1907] GOW—SPATHYEMA FOETIDA 133 
is of appreciable thickness (though much thinner than the wall of 
the cell in which it was developed) and is covered with minute spiny 
projections, The vegetative and generative nuclei appear faintly 
when the interior of the grain is brought into focus. When the 
pollen grain is treated with a solution of iodine green they appear 
much more clearly, and it is seen that the latter is much the larger 
of the two, The division between the two takes place just before 
the expulsion of the pollen grain from its investing cell. 
After the expulsion of the pollen grains the collapsed mother cells 
may be seen lying about and partially filling the cavity of the anther; 
but in a day or two they break down and disappear. Simultaneously 
with the disappearance of the mother-cell walls, the tapetal layer 
breaks down and the contents of the cells become scattered through- 
out the cavity of the microsporangium. By the beginning of the 
last week in March the microsporangium is filled with a mass of 
mature pollen grains. In the meantime the filaments, as a rule, 
have lengthened sufficiently to push the anthers out past the infolded 
edges of the perianth. When this has taken place the anthers dehisce 
and the pollen grains are set free. Frequently, however, the length- 
ening of the filament is delayed and the mature pollen grains remain 
in the anthers for a week or more before they are finally set free. 
This is a phase of the subject that must be reserved for future study, 
but it would seem that the development of the filament and dehis- 
cence of the anther are dependent to a certain extent on weather 
conditions. Probably, too, there is a correlation between their 
development and the development of the pistil. The dehiscence is 
along two longitudinal creases, each one of which separates the two 
microsporangia lying at the same end of the connective. 
THE MEGASPORANGIUM 
Material gathered early in February shows the ovary as a tiny 
cavity in the tissue of the receptacle, beneath the short thick style. 
The ovule at this period appears as a group of thin-walled, undifferen- 
tiated, strongly nucleate cells, projecting downward into the ovary 
and nearly filling it. As yet there is no distinction of nucellus and 
integuments. The style has pushed up far enough to bring the 
partially developed stigmatic cells even with the edges of the sepals. 
