ABSTRACT
The development of the genital system can be divided into three stages. For the first stage, sex determination involves differentiation of the indifferent gonad into either testes or ovary and is under genetic control. In the second stage, differentiation of ducts or internal genital organs occurs; during the third stage, differentiation of the external genital organs occurs. The development and differentiation of both internal and external organs depends on the presence of male or female gonads and their endocrine products.
