Testes stimulate secondary sex characteristics (testosterone).
Testes (singular, testis) are gonads that produce male’s gametes, sperm and androgens the male sex hormones.
Testes are held in a pouch of skin, called the scrotum (Keeps the testes at the proper temperature), between and slightly in front of the legs. The interior of Testes is a collection of thousands of tiny tubes called seminiferous tubules. When a boy reaches puberty his testes produce more testosterone.