The Dinosaur Connection: A Reinterpretation of T.H. Huxley's Evolutionary View MARIO A. DI GREGORIO Darwin College Cambridge, England The traditional understanding of T. H. Huxley's role in the history of evolutionary ideas has been based on certain prominent biographical, even autobiographical, material: that Huxley was a colleague of Darwin, that he was apparently forthright in his defense and exposition of Darwin's ideas almost immediately after publication of the Origin of Species, that he was - in short - "Darwin's bulldog," ~ reacting to the Or/g/n as an overdue "flash of light. ''2 Michael Bartholomew's 1975 analysis of Huxley 3 argues that there was no real turning point in Huxley's scientific approach after the publication of the Origin of Species, and that even after 1859 Huxley held a basically pre-Darwinian attitude to science. Whether or not one agrees with Bartholomew's view, his article contributed to a change of perspective among scholars working on Huxley's scientific thought. A cursory examination of Huxley's scientific work reveals that he began to deploy the idea of evolution only in 1868, nine years after publication of the Origin, scarcely the response one would expect upon receipt of a blinding inspiration; Huxley's own research, in other words, seems to contradict any claim that the Origin of Species persuaded him of the value of the concept of evolution. Closer scrutiny of Huxley's work, even subsequent to 1868, reveals further that one of the obviously distinctive features of Darwin's theory - the notion of natural selection - fails to appear at all. A question therefore arises: was Huxley, despite his reputation and his self-assessment, actually a "Darwinian" at all? My own view is that after 1859, under the influence of Darwin, Huxley was persuaded of the value of evolution only as a working hypothesis in respect to the phenomena of organic nature; he supported 1. Leonard Huxley, ed., The Life and Letters of Thomas Henry Huxley, 2 vols. (New York: Appleton, 1900), I, 391. 2. Francis Darwin, ed., The Life and Letters of Charles Darwin, 3 vols. (Lon- don: Murray, 1887), II, 197_ 3. Michael Bartholomew, "Huxley's Defence of Darwin," Ann. ScL, 32 (1975), 525-535. Journal of the History of Biology, vol. 15, no. 3 (Fall 1982), pp. 397-418. 0022-5010/82/0153/0397 $02.20. Copyright © 1982 by D. Reidel Publishing Co., Dordrecht, Holland, and Boston, U.S.A. MARIO A. DI GREGORIO Darwin's theory publicly as a kind of "program" worthy of serious consideration but not yet ready for broad application because of natural selection, its basic tenet. He integrated evolution with his scientific work only after 1868, when he found the way to avoid reference to natural selection. Indeed, when he finally applied evolution to the study of animal life, it was gaining wide acceptance in scientific circles and was strongly supported by the zoological school of Jena, headed by Ernst Haeckel and Carl Gegenbaur. a The main outlines of the progression of Huxley's own zoological research indicate a striking harmony with the progression of zoology in the work of his German contemporaries and colleagues;his espousal of the idea of evolution in systematics is both chronologically and methodologically interwoven with theirs. This suggests strongly that Huxley in his own research should be seen essentially as integrated into the mainstream of the German community of zoological thought. The young Huxley had been heavily influenced by German science - especially by Karl Ernst von Baer's embryological typology - and only works conceived in that tradition were in a position to have a decisive influence on his view of descent. Gegenbaur and Haeckel were the heirs of von Baer's tradition, and they strongly supported the application of evolution to the study of animal life. Haeckel's two- volume Generelle Morphologie s was published in 1866; only two years later Huxley did start to apply the notion of evolution in his scientific research, and thereafter he consistently did so. If Huxley underwent a "conversion" to evolutionism, it took place in the late 1860s under the influence of Haeckel and German science. If one considers the views held by Huxley in the early stages of his career, this outcome was inevitable. THE ROOTS In order to understand why Haeckel had such a strong impact upon Huxley's science, one needs to consider Huxley's scientific roots. It is there that one finds the solution to the puzzling problem of Huxley's attitude to evolutionism. In the first half of the nineteenth century the theoretical problem that had preoccupied continental naturalists and Richard Owen, the 4. Georg Uschmann, Geschichte der Zoologie und der zoologischen Anstalten in Jena, 1779-1919 (Jena: Fischer, 1959). 5. Berlin: Reimer, 1866). i 398 The Dinosaur Connection: Huxley's Evolutionary View leading British morphologist, was the type concept. 6 As Emanuel Rhdl wrote, "Das Wort 'Plan' schwebte auf allen Lippen. ''7 While Georges Cuvier believed in four plans to account for the different structures detectable in the animal world, I~tienne Geoffroy St. Hilaire supported the view of a single unifying plan. Goethe's interpretation was an ideal Urplan, to which all modifications discovered in nature were to be referred. Richard Owen in Britain was a strong supporter of the existence of an ideal plan that he called the "archetype." Dov Ospovat proposes a very interesting hypothesis to which I wish to refer, since Huxley is a perfect example of the correctness of the argument. 8 Broadly speaking, Ospovat detects two different ways of interpreting natural phenomena, and these were in sharp conflict during the first half of the nineteenth century. On the one side was the tradition of Cuvier's teaching, according to which there is no unity of type, and in which the stress is on teleological adaptations. It is arguable whether the "essence" of Cuvier's view was teleology, but what is important is that this is how supporters of the rival view interpreted him. On the other side, by the 1830s a number of British biologists had repudiated what they thought was Cuvier's teleology and referred to the works of the renowned embryologist von Baer; they applied his embryological methods to the type concept and to classification as the major support for an understanding of the relationships in the living realm. Von Baer, Christian Pander, and Heinrich Rathke had given great impetus to embryology as the key to the understanding of nature. 9 Rathke in 1825 discovered the gill slits of mammalian and chick em- bryos; ~° the first volume of yon Baer's masterly f)ber Entwickelungs- geschichte der Thiere was published in 1828, and the second in 1837. ix 6. Richard Owen, The Archetype and Homologies of the Vertebrate Skeleton (London: Van Voorst, 1848). 7. Emanuel Rhdl, Geschichte der biologischen Theorien seit dern Ende des siebzehnten Jahrhunderts, 2 vols. (Leipzig: Engelmann, 1905), II, 22. 8. Dov Ospovat, The Development of Darwin's Theory: Natural History, Natural Theology, and Natural Selection, 1838-1859 (Cambridge: Cambridge University Press, 1981). 9. See E. S. Russell, form and Function (London: Murray, 1916), pp. 113- 145. 10_ Heinrich Rathke, "Kiemen bei S~iugetier," 1sis (1825), 747-749; and "Kiemen bei V6geln," Isis (1825), 1100-1101. 11. Karl Ernst yon Baer, Ober Entwickelungsgeschichte der Thiere, 2 vols. (K6nigsberg: Borntrhger, 1828/1837); the Schlussheft of the second part was edited by L. Stieda in 1888. 399 MARIO A. DI GREGORIO Von Baer lived at a time when the Naturphilosophie was taking Germany and the German-speaking countries by storm? 2 Yet the results of his inquiries are largely independent of any sympathies he may have had for the views of that highly speculative attitude to nature;~3 for von Baer's researches were based on rigorous experiments. Basically, he accepted the type concept, but used embryology to provide the major criteria for his typology. According to him, the embryological types start from a common point - hence the unity of nature is preserved; they diverge to follow distinct paths of development - accounting for the diversity detectable in nature. As Ospovat has shown, 14 von Baer's work was initially introduced to British audiences by Martin Barry, a Scottish physician who in 1836-1837 published "On the Unity of Structure in the Animal Kingdom." is This was followed by William B. Carpenter's Principles of General and Comparative Physiology. t6 In France Henri Milne-Edwards was a dedicated supporter of the use of embryology in classification; in a famous 1844 paper, partially translated into English four years later, 17 he claimed that since embryos are more similar to one another than their adult forms are, it is em- bryology which indicates the clearest affinities we can discover. In his Monographie des poissions du Vieux Rouge ou syst~me d~vonien (OM Red Sandstone) des lies Britanniques et de Russie, ta Louis Agassiz of Switzerland applied the results of embryology to the study of paleontology. He wanted to find the proper systematic place of the Devonian fish to demonstrate that types through the history of the earth, animal classes through the history of their families, and embryos through the stages of their development, experience the same phases, 12. E. R. Lankester, "Karl Ernst von Baer," The Academy, 10 (1876), 608. 13. Arthur W. Meyer, Human Generation (Stanford: Stanford University Press, 1956), pp. 6465. See also B. E. Raikov, Karl Ernst yon Baer, 1792-1876." sein Leben und sein Werk (Leipzig: Barth, 1968). 14_ Dov Ospovat, "The Influence of Karl Ernst von Baer's Embryology, 1828-1859: A Reappraisal in Light of Richard Owen's and William B.