Metaplastic charges due to vitamin A-deficiency and overstimulation with estrogen were studied in the uterus of the rat. The investigation was concerned with the following problems: (1) the role of the ovaries in producing uterine metaplasia in vitamin A-deficient rats; (2) whether uterine metaplasia which is induced by estrogen is a gradual process or a rapid one, which takes place a short time after the beginning of treatment; (3) whether the age of the animal at the start of estrogen treatment has any effect on the production of metaplasia; and (4) a cytologic comparison of the metaplastic processes resulting from vitamin A-deficiency with those resulting from overstimulation with estrogen.
The Allegheny Mountains of east-central West Virginia were imperfectly peneplained in pre-Schooley time. There is no evidence that any external base level has affected this region since uplift of the pre-Schooley surface, i.e., no peneplains controlled by a base level outside the area have developed since pre-Schooley time. The region has been lowered by differential mass-wasting ever since this uplift.
A densitometer to be used for liquids at temperatures up to ca. 1000°C and maintained in an inert atmosphere was constructed. The hydrostatic weighing method of Kohlrausch was chosen as the method most readily adaptable to the conditions imposed. This method utilises the buoyancy principle of Archimedes. The plummet was suspended from one arm of an analytical balance and immersed in the sample contained in the densitometer tube. The apparent loss in weight of the plummet upon immersion was measured by a chainomatic balance. The entire apparatus was made gas-tight; observations and manipulations of the balance were made through gas-tight seals.