116 BOTANICAL GAZETTE ' faucust 
not pushed up above the calyx lobes. The writer has examined 
at least 100 plants with this closed corolla type of flowers. In - 
every case the stamens were scarcely or not at all exserted and 
were completely composed of sterile tissue. | 
Thus far all plants that I have seen which had completely 
sterile non-exserted stamens also had closed flowers; but the 
pistillate form as described by BArRttettT also includes plants 
with corollas fully developed and reflexed, and such a flower is 
figured by him (2, fig. 3) as illustrating a typical pistillate flower. 
Various plants with expanded petals and completely _ sterile 
or indehiscent stamens are potentially only females. The rudi- 
mentary development of stamens and the character of the corolla 
may be regarded as extreme cases of loss of maleness, and the 
character of the corolla may be considered as a secondary. sex 
character associated with femaleness and appearing when male- 
ness is most completely lacking. 
From general observations of plants in the field and in a green- 
house, and from such controlled pollination as have been made, it 
appears that plants of this pistillate type are highly productive 
of seed. A few plants, however, have set no seed when exposed 
to favorable conditions for free cross-pollination, which suggests 
that the pistils of some of the pistillate plants may be impotent. 
These descriptions refer to the types of flowers that charac- 
terize the 3 forms most generally recognized, and into which 
attempts have been made to classify all individuals. Both Cor- 
RENS (4) and Bartietr (3), however, recognized that it was 
somewhat difficult to thus place all individuals observed by them. 
Such a difficulty has been very apparent in respect to the material 
studied by the writer. The variations present almost every grade 
of intermediates between the two extremes described, and seem 
to involve a series of sex intergrades or intersexes. The character 
of. flowers may be quite uniform for a plant as a whole, or there 
may be a wide range of intersexuality among the different flowers 
of a single spike, or even among the various stamens of a single 
flower. Flowers typical for some of these may be described and 
arbitrarily numbered as follows: 
