creations of separate species. The genesis of man affords innumerable illustrations of it.
When we regard the science of the genesis of man from the most general point of view, and bring together all the empirical arguments for it, then we may say to-day with perfect justice that the descent of man from an extinct tertiary primate chain is no longer a vague hypothesis, but an historical fact. Naturally this fact can not be exactly demonstrated; we can not point out the innumerable physical and chemical processes which in the course of a hundred million years have gradually led up from the simplest moner and the unicellular egg-form to the gorilla and to man. But the same thing is true of all other historical facts. We all believe that Linnæus and Laplace, Newton, and Luther, Malpighi and Aristotle once lived, although this can not be exactly demonstrated in the sense of modern physical science. We firmly believe in the existence of these and of many other heroic minds because we know the works they have left behind, and because we see the powerful influence they have had upon the history of civilization. But these indirect arguments have no more conclusive force than those which we have put forward for the vertebrate history of man.
Of many Mesozoic animals of the Jurassic period we know but a single bone, the under jaw, and Huxley has very finely explained the cause of this strange phenomenon. We all consider it settled that these animals had also upper jaws as well as other bones, although we can not certainly demonstrate it. Yet the "exact school," which considers the evolution of species as an undemonstrated hypothesis, must regard the lower jaw as the only bone in the body of these remarkable animals.
Let us now in conclusion take a hasty glance into the immediate future. I am entirely convinced that the science of the twentieth century will not only accept our doctrine of development, but will celebrate it as the most significant intellectual achievement of our time, for the illuminating beams of this sun have scattered the heavy clouds of ignorance and superstition which hitherto shrouded in impenetrable darkness the most important of all scientific problems, that of the origin of man, of his true essence, and of his place in nature. The incalculable influence of the science of the development of man upon all other branches of science, and especially upon culture, will bear the most blessed fruits. The great work which was in our century begun by Lamarck and finished by Darwin will for all time remain one of the most significant achievements of the human mind, and the monistic philosophy which we found upon its theory of evolution will not only powerfully further the perception of the truths of nature, but also their practical worth in the service of the beautiful and the good. This monism is, however, based upon the empirical data furnished by modern phylogenetic zoology.
