Another part of the body that develops rapidly during these momentous years is the bust. The breasts become large, and not only add to the beauty of the girl's person, but also manifestly prepare by increase of their glandular elements for the maternal function of suckling infants. Of less importance so far as structure is concerned, but of great importance to female loveliness and attractiveness, are the changes that occur in the clearing and brightening of the complexion, the luxuriant growth, glossiness, and improved colour of the hair, and the beauty of the eyes, which during the years which succeed puberty acquire a new and singularly attractive expression. The young girl's hands and feet do not grow in proportion with her legs and arms, and appear to be more beautifully shaped when contrasted with the more fully developed limb. With regard to the internal organs, the most important are those of the pelvis. The uterus, or womb, destined to form a safe nest for the protection of the child until it is sufficiently developed to maintain an independent existence, increases greatly in all its dimensions and undergoes certain changes in shape; and the ovaries, which are intended to furnish the ovules, or eggs (the female contribution towards future human beings), also develop both in size and in structure. Owing to rapid growth and to the want of stability of the young girl's tissues, the years immediately succeeding puberty are not only those of rapid physiological change, but they are those during which irreparable damage may be done unless those who have the care of young girls understand what these dangers are, how they are produced, and how they may be averted. With regard to the bony skeleton, lateral curvature of the spine is, in mild manifestation, very frequent, and is too common even in the higher degrees. The chief causes of this deformity are: (1) The natural softness and want of stability in the rapidly growing bones and muscles; (2) The rapid development of the bust, which throws a constantly increasing burden on these weakened muscles and bones; and (3) The general lassitude noticeable amongst girls at this time which makes them yield to the temptation to stand on one leg, to cross one leg over the other, and to write or read leaning on one elbow and bending over the table, whereas they ought to be sitting upright. Unless constant vigilance is exerted, deformity is pretty sure to occur--a deformity which always has a bad influence over the girl's health and strength, and which, in those cases where it is complicated by the pathological softness of bones found in cases of rickets, may cause serious alteration in shape and interfere with the functions of the pelvis in later life.