ape in some important respects, and particularly in the curvature of the spinal column, which is that of the lower quadruped, and does not fully acquire the curvature peculiar to the human biped until the second or third year. The hand is a mere prehensile organ like the ape's for some months, and while it possesses remarkable power of grip, it is not reached out to grasp objects till the fourth month, and even then with great uncertainty and little control. The development of the human faculty of manipulation is a long and slow process, involving fine muscles, that have been added late in racial history. Speech is another human faculty that is very slowly acquired by imitation. The first words, uttered toward the end of the first year, express feeling or desire, and do not properly denote any object or action, particular or general, or even intentionally communicate a wish. The power to denote and to communicate by words generally evolves a few months later with increasing clearness of perception.
During the first years the human being passes through the earliest and most simple stages in the more distinctly human history of man, stages of which we have scarcely a record, unless it be in the bones and instruments and ornaments of prehistoric man found in caves. This period, the period of childhood, is characterized by rapid physical growth. From the moment life begins in a human creature, there is an almost uninterrupted progressive decline in his rate of growth in size. Before birth the growth per cent. steadily diminishes during each month. In the first year after birth the growth is greater than in any succeeding year. During the first three months the child gains weight at the rate of an ounce a day. In the second year the growth in height is also greater than in any succeeding year, but not the growth in weight. Thereafter the growth is fairly uniform for several years. What is true of the general growth of the body is also true of the growth of the brain. This increases two and threefold in weight during the first year, about ten per cent. more during the second, and about the same during the third; while in the fourth year it increases more than it will during the rest of life, and is nearly full size by the sixth year.
At the seventh or eighth year there begins a retardation in growth in height and in weight, extending over several years, and most marked in the tenth. This period of retardation is the period of boyhood and girlhood, and lasts
