lly this astounding
affinity is faithful to a single species of insect, which thus becomes
the sole sponsor of the blossom, without whose association the orchid
would become extinct. A remarkable instance of this special adaptation
is seen in the great Angraecum orchid of Madagascar, described by Darwin;
and inasmuch as this species glorifies Darwin's faith in the truth of
his theory, and marks a notable victory in the long battle for its
supremacy, it affords an inspiring theme for my closing paragraphs.

Among the host of sceptics--and were they not legion?--who met this
evolutionary and revolutionary theory with incredulity, not to say
ridicule or worse, was one who thus challenged its author shortly after
the appearance of his "Fertilization of Orchids," addressing Darwin from
Madagascar substantially as follows: "Upon your theory of evolution
through natural selection all the various contrasting structural
features of the orchids have direct reference to some insect which shall
best cross-fertilize them. If an orchid has a nectary one inch long, an
insect's tongue of equivalent length is implied; a nectary six inches in
length likewise implies a tongue six inches long. What have you to say
in regard to an orchid which flourishes here in Madagascar possessing a
long nectary as slender as a knitting-needle and eleven inches in
length? On your hypothesis there must be a moth with a tongue eleven
inches long, or this nectary would never have been elaborated."

Darwin's reply was magnificent in its proof of the sublime conviction of
the truth of his belief: "The existence of an orchid with a slender
nectary eleven inches in length, and with nectar secreted at its tip, is
a conclusive demonstration of the existence of a moth with a tongue
eleven inches in length, _even though no such moth is known_."

Many of us remember the ridicule which was heaped upon him for this
apparently blind adherence to an untenable theory. But victory complete
and demoralizing to his opponents awaited this oracular utterance when
later a disciple of Darwin, led by the same spirit of faith and
conviction, visited Madagascar, and was soon able to affirm that he had
caught the moth, a huge sphinx-moth, and that its tongue measured eleven
inches in length.

[Illustration]

Here we see the prophecy of the existence of an unknown moth, founded on
the form of a blossom. At that time the moth had not been actually seen
at work on the orchid, but