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 who shall question for a moment that had the flower been visited in its twilight or moonlight haunt the murmur of humming wings about the blossom's throat would have attested the presence of the flower's affinity, for without the kiss of this identical moth the Angraecum must become extinct. No other moth can fulfil the conditions necessary to its perpetuation. The floral adaptation is such that the moth must force its large head far into the opening of the blossom in order to reach the sweets in the long nectary. In so doing the pollen becomes attached to the base of the tongue, and is withdrawn as the insect leaves the flower, and is thrust against the stigma in the next blossom visited. This was clearly demonstrated by Darwin in specimens sent to him, by means of a probe of the presumable length and diameter of the moth's tongue. Shorter-tongued moths would fail to remove the pollen, and also to reach the nectar, and would thus soon learn to realize that they were not welcome.