have been formed on the cones of extinct volcanoes. Darwin had pondered for many years over the theory which was to make him famous before he decided to bring his conclusions before the public. After considerable observation of every form of animal and vegetable life and experiments in selective breeding he concluded that the species of plants and animals now on the earth were not created in their present form, but had been evolved by unbroken descent with modification of structure from cruder forms, the remains of many of which are constantly discovered in the older rocks. He discovered in 1858 that =Alfred Russel Wallace (1822- )= had independently arrived at the same conclusions, and so it was agreed that their views should be jointly laid before the Linnæan Society. In 1859 the "Origin of Species" was published, and it was followed by a number of works bearing upon the same subject, the most notable of all being the "Descent of Man." Darwin's work on "Earth Worms," perhaps the most purely literary of all his writings, appeared the year before his death. It is not the province of a sketch of Victorian literature to discuss the many important bearings of the Darwinian hypothesis. Received with unbounded contempt by literary men so eminent as Carlyle and Ruskin, it was accepted only with qualification by men of science like Agassiz, Carpenter, and Owen; but an overwhelming majority of scientific men in England, America, and above all in Continental countries, have declared in its favour. The theory has received popular interpretation in Germany from Haeckel, and in England from Huxley, although in this connection we must not forget =George John Romanes (1848-1894)=, the author of "Animal Intelligence" and "Mental Evolution in Animals," Grant Allen, and Edward Clodd.