This is the corrected typescript of an address to the American Philosophical Society commemorating the centenary of Darwin's birth and the fiftieth anniversary of the publication of the Origin of the Species on April 23, 1909.

There are botanical notebooks which concern Bunbury's study of fossil plants in general, with special studies on the fossil plants in the Geological Society in Richmond, Virginia, and at Aix-la-Chapelle, Cape Breton Island, and Pennsylvania. There is also a historical sketch of eminent English naturalists.

Correspondence of Charles Darwin with his family, Sir William J. Hooker, Sir John W. Lubbock, William Ogle, Daniel Oliver, John Tyndall, and Sir William Ramsay, 1836-1882. (1 reel). Letters to J. Brodie-Innes, W. H. Bates, Lady Dorothy Nevill, and others (1846-1882); also letters to his wife and son and letters and papers about him (1 reel). Letters from Darwin to G. H. K. Thwaites, William B. Tegetmeier, Albany Hancock, Richard Owen, Bernhard Studer, Auguste H. Forel, J. Moulinie, A. Bohrn, Karl Christoph Vogt, François Joseph Pictet de la Rive, and others.

This collection is comprised of materials from seven repositories and includes correspondence from Banks' colleagues and explorers, such as John Hope, Josiah Wedgwood, Georg Forster, and Captain William Bligh; records of expenses for voyages and journeys; and journals kept during voyages to New Foundland and Labrador (1766) and around the world with Captain James Cook (1768-1771). Topics include botany and horticulture, marine life, and collecting specimens.

One of the most important natural historians in nineteenth century Britain, Charles Darwin provided the first compelling mechanism to account for organismal evolutionary change. Although lacking a coherent model of heredity, Darwin's natural selection has exerted an enormous influence over the biological sciences and since the introduction of Mendelian genetics, had remained the key unifying principle in the discipline. The APS Darwin Papers are a large a valuable assemblage of Darwin's correspondence with scientific colleagues, including Charles Lyell and George J. Romanes. They are included in the print version of the Correspondence of Charles Darwin (Cambridge Univ. Press).