1919] STOUT—INTERSEXES 113 
eter, and all parts were then drawn to scale. Stamens and spores 
were measured and drawn under higher magnifications. 
FIRST FORM HERMAPHRODITE (figs. 1-3, 49, 50).—This term 
has been applied by BARTLETT (2) to plants whose flowers very 
uniformly show most complete development of stamens. The 
filaments are usually twice as long as the pistils. The anthers 
are large and well developed and white in color. In face view 
when freshly dehisced (fig. 2) they measure about 2 mm. in length 
by 1.5mm. in width. The corolla lobes are well developed, with 
blades strongly reflexed when anthesis is complete. 
The pollen of numerous plants of this form was examined 
microscopically and rather extensive germination tests were made.* 
Perfect grains are almost spherical, with thin smooth walls and 
granular contents. There is much variation in the size of grains 
that appear to be perfect, the smallest being about one-third the 
diameter of the largest. There is also a considerable number of 
obviously imperfect grains with shrunken shriveled walls that 
are either empty or have hyaline contents. Such grains do not 
swell up when placed in water or in various media used in testing 
germination. Impotent grains frequently constitute 25 per cent 
of the pollen of a microscopical mount. They have always been 
found present to some extent. 
After a rather extended series of experiments it was found 
that the pollen of this form germinates well in sugar-agar media. 
The most uniformly favorable results were obtained with a 
medium of 15 per cent sugar to which 3 per cent agar was added. 
Good germination was also obtained in 15-1 and 15-5 solutions. | 
The largest tubes observed measured 3.1 mm. in length. Even 
in the case of the most complete germination not all the spores 
with granular contents germinated. No shriveled and hyaline 
spores germinated, but some of the smallest of the apparently 
perfect spores germinated. Some granular spores of all the sizes 
failed to germinate. A series of countings was made for a plant 
«In the various studies of the germinations of pollen reported in this paper the 
writer has been assisted by Lieut. M. V. REED, a former student and scholar at the 
New York Botanical Garden, and by Miss HeLtene M. Boas, laboratory assistant, 
for whose efficient aid and cooperation acknowledgment is here made. 
