Action of Cortisone on Developing Chick Embryo. ∗

Abstract

Summary

1. Chick embryos at 8 days of incubation were given one-half or one mg of cortisone acetate by injection onto the chorioallantoic membrane. 2. The one-half mg dose resulted in a reduction of the liver to approximately 86% of the control weight. 3. In the one mg series, the liver was relatively smaller and the eyes and gonads were relatively larger on the basis of 100 g of body weight. In absolute values, the entire embryo and all organs were greatly reduced in size. 4. Measurements of body length, neck, wings and legs after treatment with one mg cortisone indicated the greatest degree of growth inhibition during 8 to 10 days of incubation for all except the legs. 5. A comparison of wet and dry weights from day 10 through day 18 of incubation showed that cortisone-treated embryos retained water. This retention becomes statistically significant at 15 days of incubation.