his peaceful and happy old age was devoted to gardening.
Wallace will chiefly be remembered as a great naturalist who was also an evolutionist. He was not a trained anatomist or physiologist, nor had he the prodigious range of tested knowledge which Darwin amassed. But he was an indefatigable collector, both of specimens and of facts; and he thought about what he collected with originality and vigour. Of his services to biology, not the least was the wealth of material which he sent back during his eight years in the Malay Archipelago. On the theoretical side, his most famous achievement was his independent discovery of the principle of natural selection as a key to the method of evolution. This alone would give him a permanent place in the history of thought. But further, it was he who first called attention to the importance of many colours and markings of animals for purposes of recognition at a distance—a very fruitful idea; he pointed out an important correlation between nesting-site and brilliancy of coloration in female birds; he also amplified and strengthened the theory of warning coloration and mimicry. He was an unsparing critic of Darwin's theory of sexual selection, but on illogical and insufficient grounds; his own theory of ‘male vigour’ as the cause of brighter male plumage has little to recommend it. He came to reject the whole of the Lamarckian element in Darwin's views, and, with August Weismann, became one of the apostles of the neo-Darwinian movement.
Wallace's most solid work was, perhaps, that on geographical distribution. Here he strengthened with various new arguments J. D. Dana's principle of the permanence of the great ocean basins; pointed out how dispersal of temperate and Arctic faunas could take place even across the tropics along mountain-chains; laid stress on the cumulative effect of snow-fall and ice-accumulation in accentuating the temperature changes which led to glacial epochs; and was emphatic in support of a single system of zoo-geographical regions for the distribution of all groups of animals. His zoo-geographical work was fundamental for all subsequent investigations in this field. He himself expressed the hope that his book on the geographical distribution of animals might bear ‘a similar relation to the eleventh and twelfth chapters of the Origin of Species as Mr. Darwin's Animals And Plants under Domestication bears to the first’—a hope which has been fully justified.
As regards human evolution, Wallace was the first to point out explicitly that from an early period in man's evolutionary history, natural selection would act chiefly upon the mind, not on the body, and that therefore we should not expect further physical evolution in the human species. He also advanced some interesting observations concerning what he called ‘mouth-gesture’ in relation to the origin of language, extending the principle of onomatopoeia to great lengths.
On many other matters of scientific opinion Wallace took up a very unorthodox position. He was a convinced phrenologist, anti-vaccinationist, and spiritualist, and believed that natural evolution, while it would account for the development of man's body, must have been supplemented by a supernatural intervention to produce his soul. In politics also he was unorthodox. His socialism was highly theoretical, and his views on land nationalization extreme. A vegetarian ‘in principle,’ he found that a meat diet agreed best with him. His zeal for demonstrating scientific truth once cost him a considerable sum of money and still more vexation. In 1870 a certain Mr. J. Hampden offered £500 to any one who could prove that the earth was round. Wallace took up the challenge, and an experiment was carried out on the Bedford levels. After much dispute the stakes were awarded to Wallace; but owing to technicalities connected with the law on betting Hampden recovered the money. Not content with this, he pursued Wallace in public and private with the most violent and scurrilous invective for nearly twenty years, in spite of being twice sent to jail.
Wallace was a modest man, with a kindly nature. This showed itself in the active interest he would take in the views and plans of younger naturalists; and, together with his strong sense of justice, led him to undertake his various social crusades. It has been said that he combined the most remarkable shrewdness in dealing with natural history, with an equal credulity in dealing with his fellowmen; and, although this statement is exaggerated, there is some truth in it. There was a certain element of the crank in him; but, when he was handling the facts of nature and the ample speculations of evolutionary theory, this could not show itself; and his fondness for nature, his industry, his zeal, his love both of detailed fact and of broad generalization, and his very considerable abilities, here could find their proper scope, with the result that his name will be permanently
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