"Pincus made his name in the field of experimental biology when, in 1934, he produced rabbits in vitro by parthenogenesis. In 1944, he established the Worcester Foundation for Experimental Biology where he surrounded himself with a group of brilliant young investigators. One of them was a Chinese immigrant, Min-Chueh Chang, who repeated and refined the experiments of Makepeace and established the experimental model to study the anti-ovulatory effect of sex steroids. The impetus for converting findings of animal experiments into human hormonal contraception was given by Margaret Sanger, founder of the Planned Parenthood Federation of America (PPFA). She approached Pincus in 1951 and provided a small grant to begin hormonal contraceptive research. In the same period, John Rock, an expert in the treatment of infertility, was experimenting with the oral administration of high doses of oestrogen (diethylstilboestrol) and progesterone to induce pseudo-pregnancy in infertile women. He reasoned that high doses of sex steroids promoted the growth of the uterus and the Fallopian tubes and so restored fertility; but he also found that this treatment suppressed ovulation. The biologist Pincus and the gynaecologist Rock shared their experience and their intention to develop a hormonal oral contraceptive."