Mystery of the Red Rose
Milner, Richard, Natural History
During a brief lull in a criminal investigation ("The Adventure of the Naval Treaty"), Sherlock Holmes took a moment to smell a red rose. The flower, he remarked to his friend Dr. Watson, clearly was evidence of divine beneficence. "Our highest assurance of the goodness of Providence seems to me to rest in the flowers," proclaimed the world's greatest detective. "All other things, our powers, our desires, our food, are really necessary for our existence in the first instance. But this rose is an extra. Its smell and colour are an embellishment of life, not a condition of it. It is only goodness which gives extras, and so I say again we have much to hope from the flowers."
Holmes was not the first to follow that line of reasoning. In the late seventeenth century, the English clergymannaturalist John Ray popularized the venerable school of thought known as natural theology. By studying plants and animals, Ray believed, one could find proof of divine beneficence and providential design. A century later, another parson-naturalist, William Paley, expanded on Ray's theme. Paley's Natural Theology: or, Evidences of the Existence and Attributes of the Deity, Collected from the Appearances of Nature, first published in 1802, was studied by many aspiring naturalists, including the young Charles Darwin. Paley argued that just as a watch implies the existence of a watchmaker, so the intricate mechanisms of living things must be the handiwork of a divine artificer. Through anatomical studies of eyes, wings, and hands, the natural theologians attempted to prove that biology confirmed their theology. Or, as Holmes declaimed to Watson about flowers, "Religion . . . can be built up as an exact science by the reasoner."
Why, indeed, do flowers exist? In the seventeenth century, the German botanist Jacob Camerarius-and later the Swedish taxonomist Carolus Linnaeus, among others-had come up with a shocking answer: sex. In 1737 Linnaeus published his sexual system of botanical classification. The number of a plant's stamens, or male parts, determined the class to which Linnaeus assigned it, while the number of its female parts, or pistils, determined the subgroup, or order. He characterized some species as diandria those that have two stamens (or "husbands") on a flower with one pistil ("wife")-and others as polygamia (one "husband" with multiple "wives"), and so on. He even named a genus of pea plant Clitoria. Although Linnaeus's sexual system was widely accepted, some embarrassed professors dubbed it botanical pornography. William Smellie, who worked on the first Encyclopaedia Britannica, denounced Linnaeus for going "far beyond all decent limits" and exceeding the most "obscene romance-writer."
Half a century later, the English physician and poet Erasmus Darwin (Charles's grandfather) not only expanded on the Linnaean sexual system but popularized it in his long poem The Loves of the Plants (1791). Erasmus's lusty lyric to nature became a best-seller, but many of his contemporaries found it unthinkable that beautiful blossoms, to perpetuate themselves, required vulgar insects to crawl among their sexual parts.
In 1793 Christian Konrad Sprengel, a German schoolteacher and botanist, published a triumphantly titled book, The Secret of Nature Revealed in the Structure and Fertilization of Flowers. The "secret" he revealed was that blossoms and fragrances do indeed function to attract insects that carry and disperse pollen. Sadly for Sprengel, his book was ignored for decades.
Twenty-five years after Sprengel's death, however, Robert Brown, First Keeper of Botany at the British Museum, sent a copy to his friend Charles Darwin. "It may be doubted," wrote Darwin's son Francis years later, "whether Robert Brown ever planted a more fruitful seed than in putting such a book in such hands." Darwin was delighted and amazed, and he began a research program, based on Sprengel's ideas, to discern the fertilization mechanisms of orchids. …