sal process—a matter which the aims and objects of Darwin's work did not lead him to touch were worked out by Mr. Spencer quite irrespective of the special process of natural selection; and when Darwin's book appeared, that process fell into its place in Spencer's general system, quite naturally, as a supplementary and not in any way as a disturbing element. Thus it appears that if any one man is to be looked upon as the immediate progenitor of a doctrine which, in common phraseology, may be said to have been to some extent in the air, that man is not he who first elucidated one factor of its process in one domain of phenomena—the biological; but rather he who first seized upon it as a universal law, underlying all the phenomena of creation; in a word, it is not Charles Darwin, but Herbert Spencer.
One word only, in conclusion, about the train of causes which immediately led up to the projection of the vast work with which Mr. Spencer's name is more particularly associated—the System of Synthetic Philosophy.
It was in 1858, while he was engaged on writing an essay on the Nebular Hypothesis, that there dawned upon him the possibility of dealing in a more systematic and connected manner than he had hitherto found possible, with those foundation principles of evolution to which he had been led by the miscellaneous studies of the past eight or nine years. The germ of thought thus implanted forthwith began to develop with amazing rapidity, and before long assumed the proportions of an elaborate scheme, in which all orders of concrete phenomena were to fall into their places as illustrations of the fundamental processes of evolution. Thus the conception of evolution presented itself to him as the basis of a system of thought under which was to be generalized the complete history of the knowable universe, and by virtue of which all branches of scientific knowledge were to be unified by affiliation upon the primal laws underlying them all. Though a rough sketch of the main outlines of the system, as they occurred to him at the time, was mapped out almost immediately, it was not till the following year, 1859—a year otherwise memorable for the publication of Darwin's book—that a detailed plan of the various connected works in which these conceptions were to be developed was finally drawn up; and not till 1860 that it was given to the small handful of readers interested in such subjects in the form of a prospectus. This prospectus included a brief summary of a proposed series of ten volumes, embracing thirty-three divisions or topics; and any one who cares to take the trouble of comparing it, as it stood when it first saw the light, thirty years ago, with the contents of the different volumes and portions of volumes which have been published up to the present time, will, I think, be astounded to observe the singular correspondence between them—a