ontogeny and phylogeny founded upon progressive inheritance, between the history of the development of the germ of the individual and the history of the development of his ancestral stock. In the latter, I, at that time, distinguished ten different principal degrees within the vertebrate stock. I dwelt especially, however, upon the logical connection between the evolution of man and the theory of modification by descent; if the latter is true it gives absolute validity to the former^ "The proposition that man has developed from the lower vertebrates and, indeed, immediately from the true apes is a special deduction which must necessarily result from the general induction made by the law of the theory of descent." I showed the further development and results of this conception in the various editions of my Naturliche Schöpfungs-Geschichte (first edition, 1868; ninth edition, 1898), and my Anthropogenie (first edition, 1874; fourth edition, 1891), its firm foundation was shown in the third part of my Systematische Phylogenie (1895).
It is well known that in the course of the forty years which have passed since the first publication of Darwin's theory an extensive polemical literature has appeared, relating to both its general significance and to the evolution of man, its most important result. That the latter is indissolubly connected with the former is now generally recognized, and it is exactly this intimate connection that explains the stubborn resistance that has been shown to the entire theory of evolution by all mystical and orthodox schools, by all men who have not been able to free themselves from the traditional anthropocentric superstition. In the sharp fight that has ensued on this subject the most varied weapons have been used. We can refer here only to certain exceptions based upon empirical biological grounds; we must disregard all those numerous assaults based upon metaphysical and mystical speculations made by those ignorant of the empirical but well established facts of biology. The most important part of our task will, therefore, be the critical examination of the three evidential sciences which we place at the base of all phylogenetic researches: paleontology, comparative anatomy, and ontogeny. We must cast a glance upon the advances made during the last ten years in these three auxiliaries of the science of the evolution of man and thus ascertain the degree of certainty to which a knowledge of his origin has attained by reason of these advances.
First, we have to examine the position which modern zoology, supported by comparative anatomy, gives to man in the natural system of the animal kingdom. For the aim of the natural system itself is to establish the hypothetical family tree and all the single groups, greater or smaller, which we distinguish as classes, legions, orders, families, genera, and species in the same stock are only different twigs and branches of this tree. Now, the systematic place which should be assigned to man in consideration of all the details of his bodily structure remained for a long time doubtful. When the great Lamarck, at
