In Section XXVI. statistics have been given showing the rate of bodily growth in weight and height of both sexes. From these tables also it will be observed that in girls, between the ages of eleven and thirteen, increase in height and weight becomes more rapid than at any other period of life, while growth begins to diminish at thirteen years of age, and at the age of sixteen it begins to cease. A. similar occurrence is evident in the case of boys, but several years later. This comparatively sudden falling off in physical growth is coincident with the attainment of the period of puberty. Puberty is derived from a Latin word, puber, signifying of ripe age, or adult. The age of puberty is the period when the development of certain organs, devoted to the function of re production, so advances that the person be comes capable of discharging that function. As this period arrives, the energies, formerly de voted mainly to the building up of the general bodily structure, become largely diverted, and the increase in height and weight is thus rapidly diminished. It is just previous to the arrival of this period that the marked increase in stature and weight occurs. Both these occurrences are indications of critical stages in the life-history of the individual. The period before puberty, the prepuberic period as it is called, is a time when the nutritive processes of the body are in a condition of high activity, as is sufficiently indicated by rapid growth; and the equally rapid falling off in growth is also indicative of profound constitutional changes.
Both are periods which make exceptional de mands on the bodily powers, and which are, therefore, attended by risks of their own, spe cially so in girls, in whom the changes connected with this stage of life are more rapid than in boys. It is a time of instability, a time when all the powers of body and of mind are sensitive to slight influences and easily overbalanced. It will be well, therefore, to indicate briefly what suggestions physiology has to make to parents and guardians to aid them in their appropriate guidance of girls under their charge. First of all, and in general, reference may be made to section XXVI, where the advisability is urged of observing, at periodical times, the rate of growth in height, and the relation of height to weight, as indicative of the condition of bodily health and vigour. Any marked variation from the standard there given should lead to more detailed examination of the state of health, and, if need seem, to an examination by the family physician to ensure that nothing is wrong. In this respect girls and boys are to be treated in the same way. Some special re marks are called for, however, in regard to the dress and education of girls.