HISTORY OF ANIMALS
Menstruation begins with most girls once the breasts have risen the width of two fingers. And girls' voices also become somewhat deeper about this time. For in general, the voice of a woman is higher than that of a man, and the voices of young girls are higher than those of older women, as the voices of boys are higher than those of men: but the voices of girls are also higher than those of boys and the windpipes of virgins are narrower than those of boys. Around this time, girls are in particular need of supervision: for with the start of menstruation, the sexual drive awakens powerfully in them, so that, if they do not guard against causing, due to more urgent stimuli, an earlier development of the body than would ordinarily occur in those who do not indulge in amorous passions, the drives of lustfulness tend to last into a more mature age. For those girls who enjoy love in very young years become more wanton ... like the boys if they are not guarded on one side or on both sides. The passages widen and secretions begin to flow in this region; and at the same time the recollection of past pleasures generates a desire for their repetition. Then some become impubescent from birth and impotent due to an imperfection in the regions used for procreation; likewise also women may become impubescent from birth.