THE POPULAR SCIENCE MONTHLY.
however, cannot be overlooked by the thinking mind. They are so great that if we assumed the theory of degeneracy to be true, and so were willing to throw the whole animal kingdom backward on its tail instead of forward on its feet, we might consider them to be degenerate and "wild" men. And it is interesting to find that this is what they were formerly held to be. The early pictures of the orang and chimpanzee exemplify this notion by giving them perfectly human features and erect position, brutalized only by their hairy body. They were, in fact, assumed to be a very abandoned kind of man, and not a very elevated kind of monkey. It is thought by some tribes of men to this day that the apes could talk if they would, but they are afraid that if they do they will be made slaves of and obliged to work. From the naked white skin, through the yellow and red to the black and then to the black with hair, does, indeed, seem a gradual transition; and, if we concede the erect posture, the admission of the ape into the human family carries with it no little show of justice. It is not so long ago that we denied human rights, and both openly and impliedly consanguinity, to the negro, as to make it impossible that we should not come to regard the gorilla in a more affectionate light than we do at present. But, in point of fact, the different races of mankind represent a kinship remote in proportion to their structural differences; and most of us, perhaps, would be willing to admit at once the truth of this proposition. Science insists that it is true throughout the animal world, and expects that the time will come when it will be acknowledged, and our behavior improved by an increasing kindness on our part to our inferior and weaker fellow-inhabitants of the earth. The proof of the evolution of man we find first in the fact that for every bone and muscle or organ in man there is a corresponding one in the anthropoid apes. Having shown in this way that man is not separable from his physical characteristics, science enters into a comparison with regard to the difference in brain-power. The mass of the brain, as judged by the cubical contents of the cranium, we have seen, can be no certain criterion for the intelligence, but only of comparative value, because it was so variable in the apes and man. It is, however, a guide from a physiological point of view by which we can estimate an advance in thinking powers throughout the animal kingdom. It has been amply shown by Prof. Marsh that, as a whole, the proportion of the brain-case has increased through the succession of fossil vertebrate life from the time when coal was formed up to the present. And it can be shown that this proportion is greater in man to-day as compared with existing mammals. When we come to the structure of the mass of the brain, that of man offers no perceivable difference of importance from that of certain apes. The discussion on this point has been fully entered into by distinguished anatomists, and need not be detailed in this place. Alone, the weight offers a difference. The heaviest human brain known is given at 1,872 grammes, the lightest brain of a sane person 907 grammes, both these extremes