System that describes development of secondary sexual characteristics in puberty. Girls-stage 1 (preadolescent), breast papillae elevation only and vellus pubic hair only; stage 2, breast bud elevation and sparse, slightly coarsened pubic hair; stage 3, enlargement of breast mound and darkening and curling of pubic hair; stage 4, elevation of areola and papilla to form second mound above breast tissue and adult-type pubic hair without spread to inner thighs; stage 5 (adult), rounding of breast mound with recession on areola to mound of breast tissue and spread of adult-type pubic hair to inner thighs. Boys-stage 1 (preadolescent), genitalia of same size and proportion as in early childhood; stage 2, reddening and coarsening of scrotal skin and slight enlargement of testes and scrotum; stage 3, growth of penis in length initially followed by some increase in breadth with further increase in size of scrotum and testes; stage 4, development of glans with further enlargement of penis; stage 5 (adult), genitalia of adult size and shape.