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coasts of South America, and the voyage round the world being completed by way of New Zealand, Australia, Mauritius, St. Helena, and Brazil, and then by the Cape Verde Islands to England. The remainder of his life was devoted to work in England, work of extraordinary amount and most varied character. By this work he slowly accumulated facts, and especially the conditions under which the breeds of domesticated animals and cultivated plants come into existence, and are propagated or modified. I propose to consider more in detail the history of Darwin's life in the last lecture.

ALFRED RUSSEL WALLACE was born in Monmouthshire in 1823. As a boy he was an eager naturalist. From 1844 to 1845 he was English master at the Collegiate School at Leicester, and while there made the acquaintance of Mr. H. W. Bates, an ardent entomologist. A few years later the desire to visit tropical countries became too strong to resist, and a joint expedition took place to collect Natural History objects, and to "gather facts towards solving the problem of the Origin of Species." In 1848 he started to the mouth of the Amazon, and worked with Bates till 1850, when Wallace moved to Rio Negro, finally returning in October 1852. His vessel was destroyed by fire, and he spent ten days in an open boat on the sea in the mid-Atlantic. From 1854 to 1862 he spent his time in the Malay Archipelago, where animal life was most luxuriant and least affected by man. In June 1858 Darwin received from Wallace the MS. of a paper "On the Tendency of Varieties to depart indefinitely from the Original Type," this being the same conclusion at which Darwin himself had arrived. Darwin wished to publish Wallace's paper at once, but on the urgent persuasion of Sir Joseph Hooker and Sir Charles Lyell he consented that extracts from one of his earlier MS. prepared in 1844, and from a letter to Professor Asa Gray in 1857, should be read at the same time. This took place at the Linnæan Society on July 1, 1858. Each man's discovery was perfectly independent, and neither knew on what lines the other was working. Full mutual recognition ensued, and most cordial intercourse and esteem.

SUMMARY. We have now traced the gradually increasing tendency towards a belief in Evolution. This was suggested in a tentative and almost cynical way by Buffon, and warmly supported by Goethe, and during the first half of the present century by Lamarck, St. Hilaire, Herbert Spencer, and others. Owing to one fatal flaw this belief failed to command anything like general acceptance. We know from fossils that the former dwellers on earth were unlike those now living, and that the doctrine of Evolution therefore involves modification. No one was able to point to the causes which could lead to such modification, or to explain how it could have come about. This was the objection which was driven home with relentless force and persistency by Cuvier, supported by all the weight of his personal authority, and the influence rightly gained by his splendid contributions to the science of Comparative Anatomy. This is the objection which in 1830 proved fatal, and which led to the triumph of Catastrophism over Evolution. The supporters of Evolution were silenced, but not convinced. In France the defeat was complete, but not so in other countries. It was clear that the attack must be made along new lines if there were to be any prospect of success. This fatal objection must be met. Was it not possible to determine the causes ? and if so, how? What could we hope to know of causes which could lead to modifications in animals of former geologic ages? Yet the answer was at hand, for seven months before Cuvier's final triumph at the Academy of Paris on July 19, 1830, appeared the first volume of Lyell's "Principles of Geology," in which the true path was indicated, and the key to the past shown to be afforded by the study of the present. If we would know what happened in former times, we should look around us and see what is taking place before our eyes. In this way Lyell gauged the forces of Nature-the power of running water, the force of the tides, the effect of frost and heat, the slow movements of upheaval and subsidence, the slow change of climate due to astronomical causes. He was able to prove that causes now acting, and causes which must have been in action from immeasurably remote periods, were competent to produce the effects we wonder at-the upheaval of mountain ranges, the excavation of valleys, &c.-without any need for external or supernatural agencies, and indeed, leaving no room for such agencies, for then there was nothing further to accomplish. The final stroke was given by Darwin and Wallace, who, working perfectly independently, set themselves deliberately to attack the problem on the lines laid down by Lyell-viz., by prolonged and detailed study of the conditions under which animal life exists at the present day. After years of patient work they were led independently to identical conclusions, which were announced simultaneously from opposite sides of the globe.

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