Data files, selected short publications, laboratory notebooks and other laboratory records, lantern slides and other photographs on Csapo's research on the progesterone hormone in the physiology of uterine function and uterine muscle contractibility. These files contain data on drug effects of progesterone, estradiol, caffeine, steroids on the ovaries and uterus in humans, rabbits and mice. Later laboratory notebooks are in Series 1, Data, 1946-1979.