SPRENGEL, CHRISTIAN KONRAD

born Sept. 22, 1750, Spandau, Ger. died April 7, 1816, Berlin German botanist and teacher whose studies of sex in plants led him to a general theory of fertilization which, basically, is accepted today. Sprengel studied theology and languages, spent some years as a schoolmaster in Spandau and Berlin, and became rector of Spandau. In pursuing botanical studies he neglected his duties, and, after his dismissal in 1794, with a pension, he went to Berlin. As a theologian, he believed that everything in nature was created for a purpose, and in observing plants he attempted to uncover the purpose of each minute part. Sprengel discovered that the nectaries (nectar-producing organs in flowers) were indicated by special colours, and he reasoned that the colour attracted insects. The insects, he found, were the means of conveying pollen from the stamen (male part) of one flower to the pistil (female part) of another. He also discovered that in many bisexual flowers the stamen and pistil mature at different times, and self-fertilization thus cannot occur; fertilization is accomplished instead by the transfer of pollen from one flower to another. The process of maturation of the male and female parts at different periods he called dichogamy, a term that is still used, and he traced the process in fine detail. He discovered that some flowers rely on the wind to transfer their pollen and studied the differences between these flowers and those fertilized by insects. Sprengel believed that his principles explained all of the characteristics of flowers, such as position, size, form, colour, odour, and time of flowering. He published his observations and thoughts in Das entdeckte Geheimnis der Natur im Bau und in der Befruchtung der Blumen (1793; The Newly Revealed Mystery of Nature in the Structure and Fertilization of Flowers). When his book was not well received, Sprengel became depressed and did not publish the results of his other botanical research. He turned to philology but did not distinguish himself in it. His book, after long neglect, was recognized in 1841 by the English naturalist Charles Darwin, who was so impressed by it that much of his own work on flowers arose from Sprengel's researches.