ed filaments and ring of anthers--one of
the latter being shown separate at the right, with its two pores and
exposed pollen. The freshly opened blossom discloses the entire ring of
anthers in perfect equilibrium, each with its two orifices closed by
close contact with the style, thus retaining the pollen. It will readily
be seen that an insect's tongue, as indicated by the needle, in probing
between them in search for nectar, must needs dislocate one or more of
the anthers, and thus release their dusty contents, while the position
of the stigma below is such as to escape all contact.

[Illustration]

In most flowers, with the exception of the orchids, the stamens and
pollen are plainly visible; but who ever sees the anthers of the
blue-flag? Surely none but the analytical botanist and the companion
insect to whom it is so artfully adjusted and so demonstrative. This
insect is likely to be either a bumblebee or a species of large fly. In
apt illustration of Sprengel's theory of the "path-finder" or
honey-guide, the insect does not alight at the centre of the flower, but
upon one of the three large drooping sepals, whose veins, converging to
the narrow trough above, indicate the path to the nectar. Closely
overarching this portion is a long and narrow curved roof--one of three
divisions to the style, each surmounting its veined sepals. Beneath this
our visiting bee disappears, and a glance at my sectional drawing shows
what happens. Concealed within, against the ridge-pole, as it were, the
anther awaits his coming, and in his passage to and from the nectar
below spreads its pollen over his head and back. Having backed out of
this segment of the blossom (A, Fig. 7), he proceeds to the next; but
the shelf-like stigma awaits him at the door, and scrapes off or rubs
off a few grains of the pollen from his back (B). Thus he continues
until the third segment is reached, from which he carries away a fresh
load of pollen to another flower. It will be seen that only the outer
side of this appendage is stigmatic, and that it is thus naturally
impossible for the blue-flag to self-fertilize--only one instance of
thousands in which the anther and stigma, though placed in the closest
proximity, and apparently even in contact--seemingly with the _design_
of self-fertilization--are actually more perfectly separated
functionally than if in separate flowers, the insect alone consummating
their affinity.

[Illustration: Fig. 7]

[Illu