178 FAMOUS GEOLOGISTS/Agassiz occupied by mountain lakes; and land ice could have moved uphill to deposit marine shells on the tops of hills in North Wales Eventually, through the theoretical work of James Croll (1875), an astronomical theory of the origin of climate change was developed, and such theory has been under discussion through to the present In America, Agassiz successfully applied his ideas to the interpretation of observations in the Great Lakes area, which he explored in 1848, finding new fish for his examination and ample evidences of glaciation (see his Lake Superior; Its Physical Character, Vegetation, and Animals, Compared with those of Other and Similar Regions [1850]), and many other regions But most of his work in the USA was zoological rather geological In particular, and in keeping with his long-held Cuvierian views, he was active in his criticism of Darwin’s evolutionary theory, which ran counter to Agassiz’s long-held beliefs about the special creation of life forms Agassiz even resisted the idea that different varieties of animals of the same species could be produced through time, from which it followed that the different human races were essentially different species! Thus, he gave ‘scientific’ comfort to racial bigots Agassiz could not comprehend how similar but different creatures of the same species could have been produced worldwide As a special creationist, that seemed to him to be the required alternative to his ‘polygenism’, and as such had to be rejected Agassiz’s views in fact succeeded in driving Lyell further into the evolutionist camp Also, because he was opposed to the idea of variation over time, Agassiz was inclined to suppose that every variety of fish he encountered represented a different species Hence his classification became inordinately unwieldy It is interesting that a figure, published in 1844, depicting the genealogy of his four main groups of fish, looks quite like a modern evolutionary tree, yet none of the ‘branches’ are shown as linking at their bases, though they ‘lean towards’ one another, so to speak, in a way that a later evolutionist might regard as suggestive The source of Agassiz’s anti-evolutionism can be traced to his contacts with Oken and German Naturphilosophie, and associated Platonism (fused with Christian beliefs), as well as Cuvier Species, for Agassiz, could be regarded as ‘types’ representing the ‘thoughts’ of the Creator Because there could be no substantial natural variation over time, events such as the Ice-Age represented catastrophes of divine origin that also offered the possibility of renewed creative activity The ‘plan’ of Creation was, he supposed, better understood by the natural historian than the theologian Agassiz was not a great geologist, despite his outstanding capacity for grasping and ordering information, and his powers as a teacher In 1865–1866, he visited South America, funded by a wealthy Bostonian, Henry Thayer, hoping to find evidences of glaciation in the tropics Seriously perturbed by Darwin’s theory, Agassiz sought new evidence to support of his long-held ideas about catastrophes and the great Ice-Age He wished to show that the event was of worldwide extent: so it should be possible to find evidence for it in the southern hemisphere, even in Amazonia In Brazil, he thought he had found the evidence he sought, but he mistook boulders produced by tropical weathering for glacial erratics, and soil produced by weathering was misidentified as glacial till His co-workers did not all agree, but Agassiz thought he had the experience and expertise to recognize glacial evidence when he saw it (though he admitted he saw no glacial striations) Agassiz’s attempt to extend his Ice-Age to equatorial regions was a failure and provided a classic example of ‘theory-laden’ observations On the other hand, his recognition and advocacy of the concept of a glacial epoch and the land-ice theory (even if not original to him) was of fundamental importance, marking the beginning of glaciology and all that followed in the study of Pleistocene geology See Also Creationism Evolution Famous Geologists: Cuvier; Darwin; Lyell; Murchison Fossil Vertebrates: Fish History of Geology From 1835 To 1900 Tertiary To Present: Pleistocene and The Ice Age Further Reading Agassiz L (1887) Geological Sketches New York: Houghton, Mifflin & Co Agassiz L (1967) Studies on Glaciers Preceded by the Dis course of Neuchaˆ tel Translated and Edited by Albert V Carozzi New York and London: Hafner Publishing Company (This volume contains an English translation of Agassiz’s Discours de Neuchaˆtel.) Andrews SM (1982) The Discovery of Fossil Fishes in Scotland up to 1845 with Checklists of Agassiz’s Figured Specimens Edinburgh: Royal Scottish Museums Brice WB and Figueiroˆ a SFdeM (2001) Charles Hartt, Louis Agassiz, and the controversy over Pleistocene glaciation in Brazil History of Science 39: 161 184 Carozzi AV (1973) Agassiz’s Influence on Geological Thinking in America Archives des Sciences Gene`ve 21: 38 Davies GL (1969) The Earth in Decay: A History of British Geomorphology 1758 1878 London: Macdonald Technical and Scientific