Abstract
1. Administration of CoCl2 induces a discontinuous three-phase hyperglycemia in the snake (n. Natrix natrix). 2. Initial hyperglycemia seems to be of adrenalinic origin, a fact demonstrated by treatment with ergotamine and reserpine resulting in no or only a negligible hyperglycemia, respectively. 3. The decrease of hyperglycemia in the interval from 6 to 9 hours is due to a hyperinsulinemia of B-pancreatic origin, a result of the property of Co of crystallizing insulin. This fact is evidenced electron microscopically by the growth of the relationship between crystallized and non-crystallized granules. 4. Finally, compensatory hyperglycemia is of A2-pancreatic origin, illustrated both by increased secretion indices of A2 cells, such as partial degranulation of the cells, as well as by increased proteinic synthesis indices, i.e. ergastoplasm development, a multitude of ribosomes, occurrence of granules of small dimensions.