The period of pubescence and adolescence in a boy is frequently associated with physical and psychologic problems. Their solution frequently determines the effectiveness and happiness of the adult. It is the obligation of the general practitioner and pediatrician in cooperation with the school authorities, training centers for boys and the family to help solve these problems.1 This requires an understanding of the mechanisms of pubescence and the ability to recognize and manage adequately their normal and abnormal variations.
MECHANISM OF PUBESCENCEThe development of a person includes a prolonged period of latency in genital growth called prepubescence ( fig. 1 A to B).2 During this time the testes do not grow but are maintained in this state of latency through the action of subthreshold amounts of hypophysial gonadotropic hormones.3 During the second decade of life the anterior hypophysis through increased secretion in the quantity of gonadotropic hormones stimulates the interstitial cells of the testes to produce androgenic hormones. These in association with other factors of maturation induce rapid growth and development of the penis, prostate, seminal vesicles, larynx, hair follicles and epiphysis. This period of rapid genital growth is called pubescence2 (fig. IB to C). The point in development when the testes have matured adequately to produce spermatozoa and the individual is capable of procreating is called puberty (C). Postpubescence or adolescence (C-D) follows this, with continued development of the primary and secondary sex char¬ acteristics to full maturity (D).
RANGE OF VARIATIONIn view of the complexity of the process of growth and maturation it is not surprising to find great varia¬ tions in normal boys 4 as to the age of onset of pubes-cence, the rate of development and the ultimate size of the genitalia. To determine the range of this variation I correlated the measurements of the penis and testes 5 with the degree of . maturation of the secondary sex characteristics in about 1,500 males selected at random. These subjects were then arbitrarily subdivided into six stages of development and maturation ( fig. 2 ). The first stage included all the prepubescents and the sixth the adolescents and physically matured individuals, while the intervening stages included all the boys dur¬ ing pubescence. The qualifying criterion for the sec¬ ond stage was the beginning of active growth of the testes and penis but no pubic hair, while the third, fourth and fifth stages included respectively the three stages of pubic hair development described by Crampton.2 In each stage I noted the range of size of the penis and testes as well as the associated secondary sex characteristics.On the basis of this classification, the age frequency distributions were plotted for the 1,500 normal boys and men ranging in age from 1 day to 25 years ( fig. 3). This chart indicates the decided variation as to physio¬ logic development at each age. It illustrates that pubescence (stage 2) may normally begin at any age from 10 to 16, w...
