There is considerable evidence that the germinal epithelium of the ovary continues active proliferation during adult reproductive life, and that some of the cells arising from these divisions contribute new ova and follicle cells. (For a review of this question see Swezy, '33). In the mouse there is some evidence that these proliferations are cyclical and that they are correlated in some way with other cyclical phenomena of reproductive activity (Allen, '23). This has recently been confirmed by Schmidt and Hoffman ( '41) for the guinea-pig.
The cyclical nature of these proliferations suggests that they may be accentuated by certain specific stimuli and that normally these stimuli may be hormonal in nature. Since at each ovulation liquor folliculi containing estrogen must come into extensive contact with the surface epithelium of the ovary, especially in animals which have a closed ovarian capsule, follicular hormone came first to mind as a possible stimulant. As shown by extensive experiments its principal action is to produce growth in cells of the genital tract of the female. The following study records attempts at local stimulation of the germinal epithelium by injecting estrogen into the ovarian capsule.
Since, even in normally rapidly growing tissue, counts of mitotic divisions are usually difficult and slow, the colchicine technique, which prevents completion of mitotic division and