FIG. 1.

Vaginal smears from hormone-treated mice. Four groups of mice were treated with either Depo (2 mg/mouse) or progesterone (2, 1, or 0.5 mg/mouse) subcutaneously. Vaginal smears were taken daily, and the stage of the cycle was determined as described in Materials and Methods. Graphs show the cycles of each mouse followed for 20 (progesterone groups) or 30 days posttreatment (Depo group). Estrus is shown by peaks on the Y axis, whereas diestrus is denoted by the baseline.