Figure 3. (A) – The sequence of events during puberty in girls. Breast bud appearance is usually before pubic hair growth; in the meantime growth velocity increases reaching the peak at Stage 4 of puberty. At this time menarche may appear. (B) – The sequence of events during puberty in boys. Pubertal development usually begins with enlargement of the testis followed by growth of pubic hair and growth of the penis. Peak height velocity is attained on average 2 years later than in girls.