Popular Science Monthly/Volume 42/February 1893/The Discovery of the Sexuality of Plants
ATTENTION was called, at one of the late meetings of the Brandenburg Society of Botanists, to the fact that the two hundredth anniversary of the discovery of sexuality in plants had recently occurred. It was in fact two hundred years since the doctor and botanist Rudolf Jakob Camerarius, professor at Tübingen, separated two feminine types of the annual mercury from a group of plants of the same kind growing in a garden, and remarked that they had hollow seeds. His report on this subject, published in the Ephemerides of the Leopoldine Academy, is dated December 28, 1691. Camerarius demonstrated that plants are reproduced like animals by means of sexual organs. Till then confused notions had been entertained on the subject, and no one had thought of submitting it to an experimental test. Camerarius found that the stamens constituted the male organ and the pistils the female organs, and published the fact in his memoir De Sexu plantarum Epistola. The thought, like many other great discoveries that are not appreciated at the time, was too remote from current ideas to be accepted, and was comparatively overlooked.
A hundred years after the discovery of Camerarius a book appeared that cast a new and living light on the question of the sexuality of plants. Like the elder one, it also was not appreciated by the students of the time. Although Camerarius had shown, between 1691 and 1698, the necessity of the intervention of the pollen in the act of the fecundation of plants or the production of the seed—or, to use one of Goethe's expressions, that plants gave themselves up, in the bosom of the flower, to the sports of love—the special destination of the different parts of the plant remained a riddle.
But flowers, with their special properties, the richness of their living colors derived visibly from the green of the leaves, the wonderful variety of their forms, and the perfumes with which they made the air fragrant, continued to attract the attention of the learned world. In 1793 a schoolmaster, the regent Christian Conrad Sprengel, of Spandau, again withdrew the veil, and showed with rare penetration, confining himself to the genus, what were the functions of the organs of the flower, and chiefly of the colored petals. The facts he disclosed, and which are now part of the incontestable patrimony of science, appeared so surprising to him that he entitled his book The Mystery of Nature unveiled in the Structure and Fecundation of Plants. He also advised the botanists of his time to study plants in vivo, in Nature, instead of contenting themselves with the examination in their studies of dried and withered specimens in a herbarium. His discovery was of so great importance to the scientific explanation of the functions of the different floral organs that it is hard to explain how his book, still remarkable and interesting, could have passed unnoticed. Incredible as it may appear, it is nevertheless true that his ingenious work remained unknown till 1862, when Charles Darwin, being occupied with the same question, found it and made it known.—Translated for The Popular Science Monthly from the Revue Scientifique.
Mr. James Ellis Humphrey, in his book on Amherst Trees, Massachusetts, speaks of the Japanese gingko as being very interesting to botanists for representing an extreme type of development in conifers, with much specialized flower and fruit, and for being the survivor down to the present time of this type, which was very abundant and widely distributed over the earth's surface in earlier geologic ages. This plant, whose natural habitat has become restricted to China and Japan, would probably itself have disappeared, like its relatives, but for the peculiarly religious significance which has in some way become attached to it. This has led to its careful preservation in the temple groves by the Chinese and Japanese priests, and it is even stated that it is known only in cultivation, having become extinct in the wild; so that we owe our knowledge of the living tree to a superstition.