artial self-fertilization and perpetuity in the
absence or neglect of their insect counterpart.

[Illustration: Fig. 14]

The numerous and conclusive demonstrations of Darwin, however, have
proved that in the competition for existence such self-fertilized
offspring quickly yield before the progeny of cross-fertilization.

But the distinctive feature of the orchids lies in the fact that this
dependence on the insect is wellnigh universally absolute. Here are a
great host of plants which are doomed to extinction if for any reason
their insect sponsors should permanently neglect them. The principal
botanical feature which differentiates the orchid from other plants lies
in the construction of the floral organs, the pistil, stigma, and
anthers here being united into a distinct part known as the column. The
pollen is, moreover, peculiar, being collected into more or less compact
masses, and variously concealed in the flower. Some of these are
club-shaped, with a viscid extremity, others of the consistency of a
sticking-plaster, and all are hidden from external view in pouches and
pockets, from which they never emerge unless withdrawn on the body of an
insect. The various devices by which this removal is insured are most
astonishing and awe-inspiring. Nor is it necessary to go to the
conservatory for a tropical specimen, as is commonly supposed. An orchid
is an orchid wherever it grows, and our native list of some fifty
species will afford examples of as strange mechanical adaptations as are
to be found among Darwin's pages. Indeed, a few of our American species
are there described. One example will suffice for present
illustration--the sweet-pogonia or grass-pink of our sedgy swamps
(_Pogonia ophioglossoides_). Its solitary rosy blossom, nodding on its
slender stem above the sedges, is always a welcome episode to the
sauntering botanist, and its perfume, suggesting ripe red raspberries,
is unique in the wild bouquet. One of these flowers is shown in profile
at Fig. 14, its various parts indexed. Concealed behind the petals is
the column, elsewhere indicated from various points of view. Attracted
by its color and fragrance, the insect seeks the flower; its
outstretched fringy lip offers a cordial invitation at its threshold,
and conducts its visitor directly to the sweets above. In his entrance,
as seen at D (Fig. 15), the narrowed passage compresses his back against
the underside of the column, forcing his head and back ag