The University of Chicago
In late winter of 1864, Charles Darwin received two folio volumes on radiolarians, a group of one-celled marine organisms that secreted siliceous skeletons of unusual geometry. The author, the young German biologist Ernst Haeckel (fig. 1), had himself drawn the figures for the extraordinary copper-etched illustrations that filled the second volume.1 The gothic beauty of the plates astonished Darwin (fig. 2 ), but he must also have been drawn to passages that applied his theory to construct the descent relations of these little known creatures. He replied to Haeckel that the volumes "were the most magnificent works which I have ever seen, & I am proud to possess a copy from the author."2 Emboldened by his own initiative in contacting the famous naturalist, Haeckel, a few days later, sent Darwin a newspaper clipping that described a meeting of the Society of German Naturalists and Physicians at Stettin, which occurred during the previous autumn. The article gave an extended and laudatory account of Haeckel's lecture defending Darwin's theory.3 Darwin immediately replied in his second letter: "I am delighted that so distinguished a naturalist should confirm & expound my views; and I can clearly see that you are one of the few who clearly understands Natural Selection."4 Darwin recognized in the young Haeckel a biologist of considerable research ability and aesthetic sense, and, moreover, a thinker who obviously appreciated his theory. Haeckel would become the foremost champion of Darwinism, not only in Germany but throughout the world. Probably more people prior to the First World War learned of evolutionary theory through his voluminous publications than through any other source. His Natürliche Schöpfungsgeschichte (1868) went through twelve German editions (1868-1919) and appeared in two English editions as The History of Creation. Erik Nordenskiöld, in the first decades of the twentieth century, judged it "the chief source of the world's knowledge of Darwinism."5 The crumbling detritus of this synthetic work can still be found scattered along the shelves of most used bookstores. Die Welträthsel, which placed evolutionary ideas in a broader philosophical and social context, sold over 100,000 copies in the year of its publication, 1899, and some three times that during the next thirty year—and this only in the German editions.6 (By contrast, during the three decades between 1859 and 1890, Darwin's Origin of Species sold only some thirty-nine thousand copies in the six English editions.7) By 1912 Die Welträthsel had been translated, according to Haeckel's own meticulous tabulations, into twenty-four languages, including Armenian, Chinese, Hebrew, Sanskrit, and Esperanto.8 The young Mohandas Gandhi had requested permission to render it into Gujarti; he believed it the scientific antidote to the deadly wars of religion plaguing India.9 Haeckel achieved many other popular successes, and, as well, produced more than twenty technical monographs on various aspects of evolutionary history and theory. These works not only informed a public, they drew to Haeckel's small university in Jena the largest share of Europe's great biologists of the next generation, among whom were the "golden" brothers Richard and Oscar Hertwig, Anton Dohrn, Hermann Fol, Eduard Strasburger, Vladimir Kovalevsky, Nikolai Miklucho-Maklai, Wilhelm Roux, and Hans Driesch. Haeckel gave currency to the idea of the "missing link" between apes and man; and in the early 1890s, Eugene Dubois, inspired by Haeckel=s ideas, actually found its remains where the great evolutionist had predicted, in the Dutch East Indies.10 Haeckel invented ecology, made numerous contributions to empirical zoology, worked out the complicated reproductive cycles of many marine invertebrates, and performed experiments and devised theories in embryology that led to ground-breaking research by his students. His "biogenetic law"—that ontogeny recapitulates phylogeny—dominated biological research for some fifty years, serving as a powerful research tool that joined new areas into a common field for the application of evolutionary theory. The "law," rendered in sepia tone, can still be found gracing contemporary textbooks in embryology (fig. 3).11
Haeckel initially adopted Darwinian Theory in 1860, while working on his first major monograph, Die Radiolarien—the work he sent to Darwin. That volume bears the imprint of the new theory. From that time to the publication of his principal theoretical statement in 1866, his two-volume Generelle Morphologie der Organismen, Haeckel formulated the chief features of his brand of evolutionary doctrine, from which he never significantly deviated. There were many considerations that led to the adoption and development of evolutionary theory during this period, but three in particular gave Haeckel’s work its distinctive shape and tone: the morphological tradition in which he was trained, the aesthetic judgment that he applied to his work, and the personal tragedy that haunted his life. And it is on these three themes that I would like to focus in this presentation.