Ovariectomies were performed on 8 squirrel monkeys. Four of the animals received 0.1 mg estradiol benzoate intramuscularly 3 times per week for 4 months. One hour prior to sacrifice all animals received H3‐thymidine. Sections of vagina, buccal mucosa and gingiva were processed for hematoxylin and eosin staining and autoradiographs. Measurements were made of the basemined membrane/mm of surface length, the number of basal cells/mm of basement membrane determined and a labeling index for basal cells established.The animals which had received estradiol benzoate exhibited a thick vaginal epithelium in contrast to the other animals which showed a thin and often ulcerated epithelial covering. The vaginal epithelium of the estrogen treated ovariectomized animals had longer rete pegs, fewer basal cells/mm of basement membrane and a higher labeling index than those animals not receiving estrogen. The epithelium of the buccal mucosa was significantly different in the same direction as the vagina by all three criteria. The gingival epithelium showed no significant differences by two of the three criteria.

Changes in oxidative enzyme and acid phosphatase activity, glycogen, ribonucleic acid (RNA), and lipid were demonstrated by histochemical technics in gingival epithelium of squirrel monkeys after experimental arteriolar occlusion. After 24 hours, glycogen and lipid content increased, and all enzyme activity, except lactic dehydrogenase, was depressed. By 72 hours, enzyme activity associated with the hexose monophosphate shunt was elevated.