general manner of living undergo a complete change. Hence we find that much of the play of young children in civilized lands has little or no reference to the serious life which comes afterwards. Such instincts, however, were developed during or before the long stretch of time of the Stone Age, when all men played hide and seek, and chased one another, and threw things, and ran, and jumped, and wrestled for exactly the same reason that makes us scan commercial articles, attend markets, and work in our studies or offices. What is observable in any nursery or playground affords a good illustration of the persistence of instincts long after the need which created them has passed away. For some reason the play instinct in most creatures tends to lapse at the time of full bodily maturity. It does not cease entirely, but apparently it no longer suffices as an incentive for the battle of life. Man in the savage state is naturally lazy and does not like to exert himself when food comes easily. When no urgent need or human authority is pushing him, he prefers to eat to repletion and then to lie in the sun or loaf. We even find this primitive habit cropping up in strenuous lands where the stimulus of moral education and competition has been at work for generations. We are all aware that, when we are lazy for any length of time, we get slack and soft. The primitive savage who lives by hunting and is in continual danger of raids from his neighbors, cannot afford to get slack. He must keep himself fit every day of life. How was this to be managed by our prehistoric forefathers when there was no fighting, with the weather soft, and a delicious fish easily to be caught quite near the dwelling? It is pretty safe to say that, owing to the want of condition--if they were not dancing tribes--they did not leave descendants which are among us in the twentieth century. It seems strange how readily a group of negroes who are apparently exhausted after a long day’s work will join in dance with their fellows, and how, when not very tired, they will in their laziest moments spring up and take vigorous exercise of this kind. Every doctor will tell you that there are plenty of women to-day who have not the strength nor the energy to do any work or to walk a couple of miles, but who will dance from evening till morning without showing any great fatigue. Among such Pagans as the Zulus and Masai, who organize themselves for war almost as well as has ever been done by the most civilized Christians, there is practically no distinction between military exercises and dancing. This is proof enough to show that dancing had a survival value throughout the long stretch of the Stone Age. Dancing taught primitive men to move in compact bodies without confusion, and especially without getting so bunched together that they could not use their weapons.