reputation for needless combativeness." What transformed Huxley's views and the views of his contemporaries who accepted Darwinism was not so much the evidence in favour of evolution contained in the _Origin_, as the illuminating doctrine of natural selection which for the first time supplied naturalists with a reasonable explanation of how evolution might have come about, both in the animal and vegetable kingdoms. As soon as this reason was provided them, they turned to the store of facts within their own knowledge, and rapidly arranged the evidence which had been lurking only partly visible in favour of the fact of evolution. It cannot be disputed that here and there earlier writers than Darwin and Wallace had suggested the possibility of natural selection acting upon existing variations so as to cause survival of the fittest. MacGillivray, the Scots naturalist, and the father of Huxley's companion on the _Rattlesnake_, had published suggestions which came exceedingly near to Darwin's theory. In 1831 Mr. Patrick Matthew had published a work on _Naval Architecture and Timber_, and in it had stated the essential principle of the Darwinian doctrine of struggle and survival. Still earlier, in 1813, a Dr. W.C. Wells, in a paper to the Royal Society on "A White Female, Part of whose Skin Resembles that of a Negro," had, as Darwin himself freely admitted, distinctly recognised the principle of natural selection--but applied it only to the races of man, and to certain characters alone. Finally, long before either of these, Aristotle himself had written, in _Physics_, ii., 8: "Why are not the things which seem the result of design, merely spontaneous variations, which, being useful, have been preserved, while others are continually eliminated as unsuitable?" None of these foreshadowings were supported by lengthy evidence, nor worked out into an elaborate theory; and it was not until Darwin had done this that we can say the birth of natural selection really took place. Huxley writes: "The suggestion that new species may result from the selective action of external conditions upon the variations from their specific type which individuals present,--and which we call 'spontaneous,' because we are ignorant of their causation,--is as wholly unknown to the historian of scientific ideas as it was to biological specialists before 1858." But that suggestion is the central idea of the origin of species, and contains the quintessence of Darwinism.