DorsEY: VARIATION IN FLORAL STRUCTURES OF VITIS 41 
the ‘‘perfect’’ and-the “imperfect hermaphrodites.”’ This dis- 
tinction was made asa result of the difference in the filaments; 
the “perfect hermaphrodite”’ having upright stamens (PLATE 1, 
FIG. 1); and the imperfect the reflexed stamens, in which the 
filaments curl back and down, bringing the anthers below the 
plane of the stigma (PLATE 1, FIG. 2). From the standpoint of 
self pollination this last mentioned position is an important con- 
sideration. 
THE COROLLA: The corolla is gamopetalous; the united petals 
“in the bud forming the “cap” (PLATE I, FIG.3 and 5). In the 
opening of the flower the petals break away at the base and remain 
united at the tips. This is one of the characters distinguishing 
Vitis from Cissus, the latter opening by breaking at the apex 
instead of at the base. 
OPENING OF THE FLOWER: In the bud the cohering petals com- 
pletely enclose the stamens and pistil. The first evidence that 
the flower is opening is the breaking away of the petals at the 
base. In most cases the break occurs at the base of one petal, the 
small fracture in the epidermis thus formed permitting further 
drying out of the surrounding tissue. Other petals break away 
at the base, curling as they break, thus separating one from another 
along the shallow sutures between. When the petals are released 
at one side, those on the opposite side hold fast. - With further 
drying out, the tension brings the cap off sidewise, until it finally 
hangs by one petal, which soon breaks away, allowing the cap to 
fall (PLATE I, FIG. 4 and 5). In other cases all the petals break 
away at about the same time, the individual petals gradually 
separating and curling up at the base, until they finally open wide 
and fall off. The cap may be only a few minutes in coming 
off, or it may remain partly open for several hours, depend- 
ing upon the environmental conditions. Sometimes the cap 
breaks at the base and comes off almost instantly, the filaments 
gradually straightening out in the cases where the stamens are 
upright, or curling backward if the stamens are normally reflexed. 
It is quite probable that the movements of the cap are pri- 
marily due to a drying out process rather than to pressure from 
the stamens. If the cap is removed, the separate petals soon curl 
up, as in the normal opening. Ina very few cases the cap breaks 
