ted between the pollen discs and
withdrawn without touching them. But here comes the remarkable and very
exceptional provision to make this contact a certainty--a
suggestive structural feature of this flower of which I am surprised
to find no mention either in our botanies or in the literature of
cross-fertilization, so far as I am familiar with its bibliography. Even
Dr. Gray's description of the fertilization device of this species makes
no mention of this singular and very important feature. The nectary
here, instead of being freely open, as in other orchids described, is
abruptly closed at the central portion by a firm protuberance or palate,
which projects downward from the base of the stigma, and closely meets
the lip below.

The throat of the nectary, thus centrally divided, presents two small
lateral openings, each of which, from the line of approach through the
much-narrowed entrance of the flower, is thus brought directly beneath
the waiting disc upon the same side. The structure is easily understood
from the two diagrams Figs. 12 and 13, both of which are indexed.

The viscid pollen-gland is here very peculiarly formed, elongated and
pointed at each end, and it is not until we witness the act of its
removal on the tongue of the butterfly that we can fully appreciate its
significance.

I have often seen butterflies at work upon this orchid, and have
observed their tongues generously decorated with the glands and remnants
of the pollen masses.

[Illustration: Fig. 13]

The series of diagrams (Fig. 14) will, I think, fully demonstrate how
this blossom utilizes the butterfly. At A we see the insect sipping, its
tongue now in contact with the elongated disc, which adheres to and
clasps it. The withdrawal of the tongue (B) removes the pollen from its
pouch. At C it is seen entirely free and upright, from which position it
quickly assumes the new attitude shown at D. As the tongue is now
inserted into the subsequent blossom this pollen mass is thrust against
the stigma (E), and a few of the pollen grains are thus withheld upon
its viscid surface as the insect departs (F).

In this orchid we thus find a distinct adaptation to the tongue of a
moth or butterfly.

Another similar device for assuring the necessary side approach is seen
in _H. flava_ (Fig. 15), a yellowish spiked species, more or less common
in swamps and rich alluvial haunts.

[Illustration: Fig. 14]

Professor Wood remarks, botanically, "The