Experimental observations on the ferret corpus luteum of pregnancy.

The pioneer work of Klein on unilaterally pregnant rabbits, rats and hamsters (Klein, 1933, 1935, 1938) established the role of the pregnant uterus in maintaining, independently of the foetuses, the histological structure and function of the corpora lutea of pregnancy. If the pregnant horn were removed from unilaterally pregnant animals in mid-pregnancy, degeneration of the corpora lutea followed, the progestational proliferation in the sterile horn broke down and a fresh ovulation took place. From these, and from hypophysectomy experiments on the pregnant rat,