On the contrary, mothers, guided by their instinct to nourish and foster their offspring, will produce a vigorous generation capable of transmitting the healthy maternal instinct so essential for the preservation of the species. For such a reason harmonious characters are more abundant in nature than injurious peculiarities. The latter, because they are injurious to the individual and to the species, cannot perpetuate themselves indefinitely. In this way there comes about a constant selection of characters. The useful qualities are handed down and preserved, while noxious characters perish and so disappear. Although disharmonies tend to the destruction of a species, they may themselves disappear without having destroyed the race in which they occur. This continuous process of natural selection, which offers so good an explanation of the transmutation and origin of species by means of preservation of useful and destruction of harmful characters, was discovered by Darwin and Wallace, and was established by the splendid researches of the former of these. Long before the appearance of man on the face of the earth, there were some happy beings well adapted to their environment, and some unhappy creatures that followed disharmonious instincts so as to imperil or to destroy their lives. Were such creatures capable of reflection and communication, plainly the fortunate among them, such as orchids and fossorial wasps, would be on the side of the optimists; they would declare this the best of all possible worlds, and insist that, to secure happiness it is necessary only to follow natural instincts. On the other hand, the disharmonious creatures, those ill adapted to the conditions of life, would be pessimistic philosophers. Consider the case of the lady-bird, driven by hunger and with a preference for honey, which searches for it on flowers and meets only with failure, or of insects driven by their instincts into the flames, only to lose their wings and their lives; such creatures, plainly, would express as their idea of the world that it was fashioned abominably, and that existence was a mistake. As for man, the creature most interesting to us, in what category does he fall? Is he a being whose nature is in harmony with the conditions in which he has to live, or is he out of harmony with his environment? A critical examination is needed to answer these questions, and to such an examination the pages to follow are devoted. CHAPTER III SIMIAN ORIGIN OF MAN Relationship of the human species with anthropoid apes- To understand human nature it is necessary first to give an account of the origin of man. This question has preoccupied mankind for ages, and for a long time it was believed that a solution of the problem was to be found in religious dogmas. Man was regarded as being of supernatural origin, the result of a special creation. Scientific criticism has now shown that there are no grounds for such a conclusion. Nearly half a century ago Darwin applied to man his discovery of the principle of natural selection, and of the part played by that in the origin and transmutation of species. Soon after the publication of the "Origin of Species," attention was given to the special case of man. In 1863 Huxley * gave an admirable review of the problem in his work on "Man's Place in Nature." He brought forward arguments of the highest scientific validity in support of the thesis that man is descended from animals, and that he is a mammal most nearly related to monkeys, and among these to the anthropoid apes. In spite of this masterly exposition, there are still persons of high intelligence and superior education who declare that science has not yet answered the question as to whence he came, and that the theory of evolution will never provide an answer.† Close examination of the structure of man has proved, in the most definite fashion, the existence of a near kinship with the higher monkeys, or anthropoids. When the chimpanzee and the ourang-outang were discovered, comparison became inevitable, and many naturalists, including the great Linnæus, saw that the human race must find its place in classification near the anthropoids. Now that all the details of the human organisation have been studied, and the anatomical structures of man and large monkeys without tails have been compared, bone with bone and muscle with muscle, a truly astonishing analogy between these organisms is made manifest, an analogy apparent in every detail. It is known that in the natural history of mammals the teeth play an important part as a means of determining differences and relationships. The dentition of man bears a very great resemblance to that of anthropoids. Every one knows the milk teeth and the permanent teeth of man. The anthropoid apes bear in this respect an astonishing likeness to man. The number (thirty-two in the adult), the form and general arrangement Republished, with other essays, as Man's Place in Nature," Macmillan, London, 1894. † Brunetière, Revue des Deux Mondes, Jan. 1, 1895, p. 99. of the crown, are identical in man and anthropoid apes. The differences are to be found only in minor details, such as the exact shape and relative dimensions and the number of cusps. It can be said in a general way that in the anthropoid apes the teeth are more strongly developed than in man. The canines are much longer and the roots of the pre-molars are more complex in the gorilla than in man. But the fact must not be lost sight of, that all these differences are less pronounced than those which exist between the dentition of anthropoid apes and that of all other monkeys. Even in the cynocephalous monkeys, those that most nearly approach the anthropoids, the teeth exhibit marked differences. Thus, the forms of the upper molars are quite different in the baboon and in the gorilla. The canines are longer, and the pre-molars and molars are still more complex in the baboon. In the monkeys of the New World, the dentition differs still more from that of man and anthropoids. Instead of thirty-two teeth, they possess thirty-six in the adult condition. The number of pre-molars is twelve instead of eight. The general form and the crowns of the molars are very different from those of anthropoid apes. These considerations led Huxley to conclude that "it is obvious that, greatly as the dentition of the highest ape differs from that of man, it differs far more widely from that of the lower and lowest apes." * Another character which shows that anthropoids are nearer man than other monkeys is furnished by the anatomy of the sacrum. In monkeys as a whole the sacrum is composed of three, or rarely four, vertebræ, while in anthropoid apes it contains five, that is to say just as many as in man. * Loc. cit. p. 116. |