[Mr. Wallace, one of the greatest naturalists of the age, discovered the law of natural selection independently of Darwin, and about the same time. Among his works are "The Malay Archipelago," "Island Life," and "Darwinism." From "Natural Selection," which was published by Macmillan & Co., 1871, the following extracts are taken. The theme has received important development at the hands of Professor E. B. Poulton, in his "The Colours of Animals," International Scientific Series, 1890: and in F. E. Beddard's "Animal Colouration"; London, Swan Sonnenschein; N. Y., Macmillan, 1892.] There is no more convincing proof of the truth of a comprehensive theory, than its power of absorbing and finding a place for new facts, and its capability of interpreting phenomena which had been previously looked upon as unaccountable anomalies. It is thus that the law of universal gravitation and the undulatory theory of light have become established and universally accepted by men of science. Fact after fact has been brought forward as being apparently inconsistent with them, and one after another these very facts have been shown to be the consequences of the laws they were at first supposed to disprove. A false theory will never stand this test. Advancing knowledge brings to light whole groups of facts which it cannot deal with, and its advocates steadily decrease in numbers, notwithstanding the ability and scientific skill with which it has been supported. The course of a true theory is very different, as may be well seen by the progress of opinion on the subject of natural selection. In less than eight years "The Origin of Species" has produced conviction in the minds of a majority of the most eminent living men of science. New facts, new problems, new difficulties as they arise are accepted, solved or removed by this theory; and its principles are illustrated by the progress and conclusions of every well established branch of human knowledge. It is the object of the present essay to show how it has recently been applied to connect together and explain a variety of curious facts which had long been considered as inexplicable anomalies.