Sun Simiao pointed out that: “the way of birth, the beginning of the child, the method of seeking children, the man is noble in the clear mind to raise its essence, the woman should be calm and determined to raise its blood”, the Ming Dynasty Wanquan also said: “the man to the essence of the main, the woman to the blood of the main, the Yang essence of the overflow of diarrhea and inexhaustible, the blood of the Yin time under the offense, Yin and Yang exchange of fluent, the essence of the blood together coagulation, the combination of the embryo and the childbearing nourishment carry on,” Zhang Jingyue pointed out that: “All the widowed desire to get of the men and women, expensive and life, more than one man and woman desire to get of the men and women, turbid and die young”.