Fig. 120.—Alfred Russel Wallace, Born 1823.
And Wallace gives this account: "In February, 1858, I was suffering from a rather severe attack of intermittent fever at Ternate, in the Moluccas; and one day, while lying on my bed during the cold fit, wrapped in blankets, though the thermometer was at 88° Fahr., the problem again presented itself to me, and something led me to think of the 'positive checks' described by Malthus in his Essay on Population, a work I had read several years before, and which had made a deep and permanent impression on my mind. These checks—war, disease, famine, and the like—must, it occurred to me, act on animals as well as man. Then I thought of the enormously rapid multiplication of animals, causing these checks to be much more effective in them than in the case of man; and while pondering vaguely on this fact, there suddenly flashed upon me the idea of the survival of the fittest—that the individuals removed by these checks must be on the whole inferior to those that survived. In the two hours that elapsed before my ague fit was over, I had thought out almost the whole of the theory; and the same evening I sketched the draught of my paper, and in the two succeeding evenings wrote it out in full, and sent it by the next post to Mr. Darwin."
It thus appears that the announcement of the Darwin-Wallace theory of natural selection was made in 1858, and in the following year was published the book, the famous Origin of Species, upon which Darwin had been working when he received Mr. Wallace's essay. Darwin spoke of this work as an outline, a sort of introduction to other works that were in the course of preparation. His subsequent works upon Animals and Plants under Domestication, The Descent of Man, etc., etc., expanded his theory, but none of them effected so much stir in the intellectual world as the Origin of Species.
This skeleton outline should be filled out by reading Darwin's Life and Letters, by his son, and the complete papers of Darwin and Wallace, as originally published in the Journal of the Linnæan Society. The original papers are reproduced in the Popular Science Monthly for November, 1901.
Wallace was born in 1823, and is still living. He shares with Darwin the credit of propounding the theory of natural selection, and he is notable also for the publication of important books, as the Malay Archipelago, The Geographical Distribution of Animals, The Wonderful Century, etc.
The Spread of the Doctrine of Organic Evolution. Huxley.—Darwin was of a quiet habit, not aggressive in the defense of his views. His theory provoked so much opposition that it needed some defenders of the pugnacious type. In England such a man was found in Thomas Henry Huxley (1825-1895). He was one of the greatest popular exponents of science of the nineteenth century; a man of most thorough and exact scholarship, with a keen, analytical mind that went directly to the center of questions under consideration, and powers as a writer that gave him a wide circle of readers. He was magnificently sincere in his fight for the prevalence of intellectual honesty. Doubtless he will be longer remembered for this service than for anything else.
Fig. 121.—Thomas Henry Huxley, 1825-1895.
He defended the doctrine of evolution, not only against oratorical attacks like that of Bishop Wilberforce, but against well-considered arguments and more worthy opponents. He advanced the standing of the theory in a less direct way by urging the pursuit of scientific studies by high-school and university students, and by bringing science closer to the people. He was a pioneer in the laboratory teaching of biology, and his Manual has been, ever since its publication in 1874, the inspiration and the model for writers of directions for practical work in that field.