[22] M. A. Czaplicka, _My Siberian Year_, p. 230. [23] Ripley, _The Races of Europe_, pp. 76-7. [24] Darwin, _Animals and Plants under Domestication_, Pop. ed., II. p. 308. [25] The contents of this section lie outside my own studies, and have been taken from various books of Geology and Palæontology: I must especially mention Prof. Osborne’s _Age of Mammals_ (1910) and Prof. Scott’s _Land Mammals in the Western Hemisphere_ (1913). I have also profited by inspecting the Palæontological Gallery at South Kensington with the help of its excellent Guide-Book. [26] A. Keith, _The Human Body_, p. 58. [27] _Travels and Researches in Western Africa_, ch. vii. CHAPTER II ON THE DIFFERENTIATION OF THE HUMAN FROM THE ANTHROPOID MIND § 1. HEREDITY, ADAPTATION, ACCOMMODATION Following the general belief that Man is descended from a stock nearly allied to the greater anthropoids—Orang, Chimpanzee, Gorilla—we may assume that his mental endowments were once much the same as theirs; and that, so far as they are still the same, _heredity_ sufficiently explains his having them. Thus the senses, perception, the simpler forms of comparison and inference, the appetites and many of the instincts and emotions are common to us with the apes, are seen in our children under three years old, and (in short) constitute that generic consciousness (as I have called it) from which the human mind in general and the peculiar traits of races and individuals are differentiated. So much for heredity; but the differences of the human from the anthropoid mind, alike in intelligence and in character, are enormous, and must be accounted for in some other way. Allowing for some original specific difference which we can hardly hope to discover, the changes that have taken place may be considered as the result of _adaptation_ to those habits of life under which our species (now ranking zoologically as a Family) has been developed. And this adaptation I shall assume to have been brought about under conditions of natural selection: human races, as we now see them, being the survivors of many variations, more or less successful, and the others having been destroyed. For good judges are of opinion that, amongst the discovered remains of ancient specimens of the human family, some that exhibit marked deviations from the modern type—Neanderthalensis, Eoanthropus, Pithecanthropus—should be regarded not as belonging to our ancestral line, but rather as representing distinct species that have failed in the struggle for existence.[28]