e blossom. The entrance is thus
much narrowed. If we insert a pin in this V-shaped entrance it comes in
contact with the sensitive membrane below the anther, and it is
immediately ruptured, as shown at Fig. 20, D. The sticky gland is
brought into immediate contact, and clasps the pin, which, now being
withdrawn, brings away the pollen, as in E and F. Thus it is naturally
removed on the tongue of its sipping bee.

[Illustration: Fig. 19]

[Illustration: Fig. 21]

The further demonstration will be better shown by profile sections (Fig.
21). Nectar is secreted in the hollow of the lip indicated, somewhat as
in the cypripedium. If we now imitate with a probe the habit of the
insect and the action of its tongue, we may witness a beautiful
contrivance for cross-fertilization. We will suppose the bee to be
working at the top of the spike. He thrusts his tongue into the narrow
opening (G). The membrane protecting the pollen-gland, thus surely
touched, ruptures as described, and the exposed gland attaches itself to
the tongue, being withdrawn as at H, and located on the insect's tongue,
as in F, Fig. 20. The bee leaves this flower cluster and flies to
another, upon which it will usually begin operation at the bottom. The
flower thus first encountered is an old bloom, as in Fig. 19, D. Its
sepals are more spreading, the lip slightly lowered, and the column so
changed as to present the plane of the stigma, before out of sight, in
such a new position as to invariably receive the pollen. The tongue of a
bee entering this flower conveys the pollen directly against the
stigmatic surface (I), which retains its disentangled fecundating
grains, as at J, and the flower's functional adaptations are fulfilled.

[Illustration: Fig. 20]

[Illustration: A. Extended. B. Folded beneath the head.]

In the allied Spiranthes, or "Lady's-Tresses," a somewhat similar
mechanism prevails, by which fertilization is largely effected by the
changed position or angle of the stigma plane.

And thus we might proceed through all the orchid genera, each new
device, though based upon one of the foregoing plans, affording its new
surprise in its special modification in adaptation to its insect
sponsor--all these various shapes, folds of petals, positions, colors,
the size, length, and thickness of nectary, the relative positions of
pollen and stigma, embodying an expression of welcome to the insect with
which its life is so marvellously linked. Occasiona