DISEASES OF PUBERTY The chief expression of beginning sexual power is the developing specific activity of the embryonic glands. Spermatozoa mature in the testicles of a boy, ova in the ovaries of a girl. In the case of the latter, the fully developed ova are discharged regularly, about every 4 weeks with the evidences of menstruation. Nocturnal, involuntary discharges of semen begin in boys, generally before they are completely developed sexually; these take place at first at long intervals.
these events which constitute the nucleus of the development, many changes are to be observed in body and mind, the sum total of which we call the symptoms of puberty. Striking changes take place in the sexual organs; the external and internal genitalia become more vascular and grow rapidly; axillary and pubic hair appear, "Pubertas a Aube dicitur"; in boys the beard begins to grow and hair appears on the rest of the body, especially on the chest and back. The figure, which up to this time has been childish, changes in a typical way, the shoulders become broader because the thorax in creases greatly in breadth; its circumference grows in 3 years about 12 cm.; the maximum capacity of the lungs often increases 500 c.c. in a year. The breathing in females becomes more and more costal in type, in males abdominal, whereas before this the character often va ried. In addition to the great general bodily growth which attends the development of puberty the sexual type becomes more apparent. The breasts of girls protrude and increase in consequence of the development of fat and connective tissue, moreover the branching of glandular ducts proceeds, though glandular tissue capable of function develops only in the periphery of the breasts. The female pelvis widens in all dimensions and the thighs and buttocks become rounder and fuller in consequence of a marked deposit of fat. The plastic development of the extremities in youth is caused by a growth of the skeleton but also by an increase in the size and firmness of the muscles.
Of the changes in the inner organs that of the larynx, which brings about the change of voice, is first to be mentioned. This is in general more marked in boys, in whom the larynx grows rapidly, especially in the transverse diameter with corresponding increase in length of the vocal cords; the female larynx on the other hand, grows more in the vertical diameter. Girls' voices break less often than boys and generally only
in singing, though they become more resonant and fuller. Boys' voices are rough and harsh and after a time of frequent breaking become filially an octave lower. The connection between change of voice and sexual development is evidenced by the well-known fact that boys, castrated before puberty, show a decidedly smaller growth of the larynx and retain very high voices. The dependence of the development of the sexual character upon the growth of the embryonic glands can be well seen in these individuals; males castrated before puberty show in addition a diminished growth of beard, slender figures, narrow chests and broad pelves.
The connection between the thyroid gland and puberty and growth rests upon numerous observations. The thyroid gland, in which a con gestive and parenchymatous swelling occurs before and during puberty causing an increase in the organ of 15 per cent, and at the time of men struation frequently 60 per cent. (Fischer, Freund), has also a decided influence upon bony growth. Thyreoidin can be used satisfactorily to influence a cessation of this, so long as the cartilages are not calcified (Denis, ,J. J. Schmidt). Dysthyreoidia has not only a restraining influence upon physical, but also upon mental development and further, the special morphological growth of the genital organs of both sexes and the de velopment of puberty are dependent. upon the normal growth and func tion of the thyroid gland (Hertoghe). The connection between the thyroid gland and the sexual organs is shown also by pathological facts such as the diminution of sexual power in men and anomalies of mens truation and atrophy of the sexual organs in many women during the course of Basedow's disease, the development of which not infrequently dates back to the age of puberty (Grawitz). If, as Hofmeister says, the thymus gland can take the place of the thyroid gland after experi mental extirpation of the latter, the physiological importance of the thymus disappears with its beginning involution which takes place often long before the child enters upon puberty.