The purpose of circumcision is probably to prolong the sex act, for the bare glans is less sensitive than the covered one. Friederici says (p. 89) that the black boys congregating on the stations and plantations frequently discuss these matters amongst themselves; they know that the glans of the circumcised is much less sensitive than that of the uncircumcised. Many authors are of the opinion that the abscission or incision of the foreskin in boys has the purpose of making cohabitation easier in later years, as this is often made difficult by phimosis (tightness of the foreskin). Külz (p. 40) found that among the youthful plantation workers in New Mecklenburg nearly a quarter were afflicted with phimosis, and often to such a degree that normal sex functioning was quite impossible. But such a condition does not seem to prevail among most of the primitive peoples practising circumcision. And, further, of what use would mutilations be that had nothing to do with tightness of the foreskin?
The prolonged festivals and elaborate ceremonials which are so often connected with the circumcision of boys and of girls, or with their admission to the state of manhood and womanhood (without accompanying circumcision), are intended to preserve the event in the memory. The long ceremony is deeply impressed upon the mind, and forms a firm nucleus round which other memories cluster which otherwise would be lost in the humdrum of ordinary life. How could the time of entry into manhood remain without ceremonious festival? This seems all the more necessary because the growth into manhood is gradual and almost unnoticeable, and if there were no ceremony, it would pass without making any impression. It is therefore the intention not only to give expression to the beginning virility, but above all to the admission into the league of youth (Schurtz, pp. 95, 96).
VIII MATURITY AND DECLINE
Among all human races the signs of maturity appear later and less distinctly in the male than in the female. In Europeans the period of puberty coincides with the second period of increased bodily growth, which ceases in the male between the sixteenth and the eighteenth year, and in the female between the fourteenth and the sixteenth year. The end of the puberty period may, however, in individual cases, be postponed for some years. The exact time of the advent of sex maturity, which, on account of their menstruation, can be fixed much more readily in girls than in boys, varies not only individually, but racially. The same applies to the difference in time between the advent of maturity and the cessation of bodily growth. Sexual maturity, as well as the cessation of bodily growth, takes place much earlier in Europeans than in some of the primitive peoples. Among other primitive peoples, however, maturity occurs comparatively late, and bodily growth ceases shortly after. To the latter belong certainly some of the peoples living in the tropics.
The opinion still prevails that climate has a considerable influence on the advent of maturity. Rudolf Martin (1915) remarks: "Races living in the tropics grow more quickly and mature earlier than the races living in temperate zones. This is undoubtedly due to the earlier advent of puberty."
As regards the Japanese, E. Baelz had already in 1891 disputed the statement that they mature early. He found, however, that the growth of both sexes ceases in Japan earlier than in Europe; still sex maturity in the female does not occur earlier. According to the concordant statements of female teachers of various girls' schools, the Japanese girls, in fact, reach maturity later than European girls, and half-caste girls take a medium position.
Since then reliable data about the advent of maturity among non-European races have seldom been given, but those to hand show that most probably even among coloured primitive people puberty generally occurs late.
Very important material has been collected by O. Reche in Matupi (New Pomerania, Melanesia), with the assistance of the Catholic mission of the place. He found that the rhythm of growth of the Melanesians corresponds on the whole to that of the Europeans, except that the growth ceases altogether a few years earlier. Development in height is finished on the whole in girls at the beginning of the seventeenth year, and in boys in the eighteenth year. But, as regards the advent of puberty, Reche's researches led to the surprising result that all Matupi girls, with the exception of those seventeen years old, had not yet menstruated. Reche remarks that this strikingly late appearance of menstruation is also known to the missionaries, because in order to prevent early marriages they only consent to the marriage of a girl after the first menstruation has taken place. Reche's experience is in strong contradiction to the belief formerly taken for granted, for puberty occurs among these inhabitants of the tropics not only not earlier, but, on the contrary, later than with the Europeans living in temperate climates. Of importance is the fact that in the Matupi natives puberty coincides with the highest point of the curve of growth, namely, with the end of the development in height. Puberty commences when growth ceases. It almost seems as if the advent of maturity absorbs all the strength and hinders further growth. It is quite different with Europeans in this respect: the beginning of puberty falls with them in the second period of growth (in boys the twelfth to the sixteenth, in girls the eleventh to the fourteenth year), and therefore long before growth ceases altogether.