"Let us not underrate the value of a fact; it will one day flower in a truth." The defects in Sprengel's work were, after all, not actual defects. The error lay simply in his interpretation of his carefully noted facts. As Hermann Müller has said, "Sprengel's investigations afford an example of how even work that is rich in acute observation and happy interpretation may remain inoperative if the idea at its foundation is defective." What, then, was the flaw in Sprengel's work? Simply that he had seen but
Thus we see the four successive steps in progressive knowledge, from Grew in 1682, Linnæus, 1735, Sprengel, 1787, to Darwin, 1857-1858, and realize with astonishment that it has taken over one hundred and seventy-five years for humanity to learn this apparently simple lesson, which for untold centuries has been noised abroad on the murmuring wings of every bee in the meadow, and demonstrated in almost every flower.
This infinite field now open before him, Darwin began his investigations, and the whole world knows his triumphs. He has been followed by a host of disciples, to whom his books have come as an inspiration and ennobling impulse. Hildebrand, Delpino, Axell, Lubbock, and, latest and perhaps most conspicuous, Hermann Müller, to whom the American reader is especially referred. "The Fertilization of Flowers," by this most scholarly and indefatigable chronicler, presents the most complete compendium and bibliography of the literature on the subject that have yet appeared. Even to the unscientific reader it will prove full of revelations of this awe-inspiring interassociation and interdependence of the flower and the insect.
Many years ago the grangers of Australia determined to introduce our red clover into that country, the plant not being native there. They imported American seed, and sowed it, with the result of a crop luxuriant in foliage and bloom, but not a seed for future sowing! Why? Because the American bumblebee had not been consulted in the transaction. The clover and the bee are inseparable counterparts, and the plant refuses to become reconciled to the separation. Upon the introduction and naturalization of the American bumblebee, however, the transported clover became reconciled to its new habitat, and now flourishes in fruition as well as bloom.