For a period of fifty years the progress of interpretation was completely arrested. The flowers remained without a champion until 1787, when Sprengel began his investigations, based upon the unsolved mysteries of color and markings of petals, fragrance, nectar, and visiting insects. The prevalent idea of the insect being a mere idle accessory to the flower found no favor with him. He chose to believe that some deep plan must lie beneath this universal association. At the inception of this conviction he chanced to observe in the flower of the wild geranium (
His labors were now concentrated on the work of interpretation, until at length his researches, covering a period of two or three years, were given to the world. In a volume bearing the following victorious title, "The Secrets of Nature in Forms and Fertilization of Flowers Discovered," he presented a vast chronicle of astonishing facts. The previous discoveries of Grew and Linnæus were right so far as they went-viz., "the pollen must reach the stigma"-but those learned authorities had missed the true secret of the process. In proof of which Sprengel showed that in a great many flowers, as I have shown at C (Fig. 3), this deposit of pollen is naturally impossible, owing to the relative position of the floral parts, and that the pollen could not reach the stigma except by artificial aid. He then announced his startling theory:
1. "Flowers are fertilized by insects."
2. Insects in approaching the nectar brush the pollen from the anthers with various hairy parts of their bodies, and in their motions convey it to the stigma.
But Sprengel's seeming victory was doomed to be turned to defeat. The true "secret" was yet unrevealed in his pages. He had given a poser to Linnæus (C), yet his own work abounded with similar strange inconsistencies, which, while being scarcely admitted by himself, or ingeniously explained, were nevertheless fatal to the full recognition of his wonderful researches. For seventy years his book lay almost unnoticed.
