Page:Popular Science Monthly Volume 45.djvu/26

14, quietly settled down to his work, and soon astonished the world with the first published results, such as his book on Coral Reefs, and the monograph on the Cirripedia; and, finally, how he presented his paper and followed it up with treatises which make him one of the great leaders in the history of human thought.

The scientific world realizes, too, more and more the power of character shown by Darwin in all this great career: the faculty of silence, the reserve of strength seen in keeping his great thought—his idea of evolution by natural selection—under silent study and meditation for nearly twenty years, giving no hint of it to the world at large, but working in every field to secure proofs or disproofs, and accumulating masses of precious material for the solution of the questions involved.

To one man only did he reveal his thought: to Dr. Joseph Hooker, to whom in 1844—under the seal of secrecy—he gave a summary of his conclusions. Not until fourteen years later occurred the event which showed him that the fullness of time had come, the letter from Alfred Russel Wallace, to whom, in brilliant researches during the decade from 1848 to 1858, in Brazil and in the Malay Archipelago, the same truth of evolution by natural selection had been revealed. Among the proofs that scientific study does no injury to the more delicate shades of sentiment is the well-known story of this letter. With it Wallace sent Darwin a memoir, which he asked him to present to the Linnæan Society; on examining it, Darwin found that Wallace had independently arrived at conclusions similar to his own—possibly had deprived him of fame; but Darwin was loyal to his friend, and his friend remained ever loyal to him. He publicly presented the paper from Wallace, and with it bis own conclusions, and the date of this presentation—July 1, 1858—separates two epochs in the history, not merely of natural science, but of human thought.

In the following year, 1859, came the first installment of his thought in its fuller development—his work on The Origin of Species. In this, one at least of the great secrets at the heart of the evolutionary process, which had baffled the long line of investigators and philosophers from the days of Aristotle, was more broadly revealed. The effective mechanism of evolution was shown at work in three ascertained facts: in the struggle for existence among organized beings; in the survival of the fittest; and in heredity. These facts were presented with such wealth of minute research, wide observation, and patient collation, with such transparent honesty and judicial fairness, that they at once commanded the world's attention. It was the outcome of thirty years' work and thought by a worker and thinker of genius, but it was yet more than that—it was the outcome, also, of the work