Darwin imagined grandly, and verified his imaginings as far as one man's life suffices; and no man can do more. And Darwin won, as far as a man can win, success during his lifetime. As Professor Huxley said, in lecturing on "The Coming of Age of 'The Origin of Species,'" "the foremost men of science in every country are either avowed champions of its leading doctrines, or at any rate abstain from opposing them." His prescience has in less than a generation been justified by the discovery of intermediate fossil forms of animals too numerous to be here recounted. The break between vertebrate and invertebrate animals, between flowering and non-flowering plants, between animal and plant, is now bridged over by discoveries in the life histories of animals and plants which exist to-day. Embryo animals and plants are now known to go through stages which repeat and condense the upward ascent of life; and they give us information of the greatest value as to lost stages in the path. We can, as it were, see the actual track through which evolution may have proceeded. "Thus," says Professor Huxley, "if the doctrine of evolution had not existed, palæontologists must have invented it, so irresistibly is it forced upon the mind by the study of the remains of the Tertiary mammalia which have been brought to light since 1859;" and again, "so far as the animal world is concerned, evolution is no longer a speculation, but a statement of historical fact." As to the limits of the truth of Darwin's theory, Professor Huxley, writing on "Evolution in Biology," in "The Encyclopædia Britannica," says: "How far natural selection suffices for the production of species remains to be seen. Few can doubt that, if not the whole cause, it is a very important factor in that operation; and that it must play a great part in the sorting out of varieties into those which are transitory, and those which are permanent. But the causes and conditions of variation have yet to be thoroughly explored; and the importance of natural selection will not be impaired, even if further inquiries should prove that variability is definite, and is determined in certain directions rather than in others, by conditions inherent in that which varies." We have not space to describe the importance of the work Darwin did in, or bearing on, entomology, changing its face and vastly elevating its importance. A volume might be compiled from his writings on this subject, as reference to Professor Riley's excellent summary (Darwin Memorial Meeting, Washington, 1882) will readily show. Nor can we recount his important work in other branches of biology further than has been already done in the foregoing pages. To do so would require much more than a volume of this size.