Sodium, potassium, calcium, magnesium, chloride, and water analyses were carried out on tissues of three polar bears, and on the blood of the barren ground caribou. The electrolyte and water concentrations in heart, liver, skeletal muscle, tendon, and plasma of the polar bear were not essentially different from those found in other mammals. Red blood cells of this branch of the bear family, Ursidae, resembled those of other members of the order, Carnivora, in containing a high sodium, 91.1 meq, and a low potassium concentration, 4.1 meq, per kilogram of packed cells; they also contained 4.9 meq of magnesium per kilogram of packed cells. Caribou red cells had 29.6 meq of sodium per kilogram of packed cells and 1.7 meq of calcium per liter of packed cells, and in this electrolyte pattern resembled other members of the order Artiodactyla, which is distinguished by the variability among the families in the Na–K balance of the erythrocytes. The data reported here are of special interest because of the genetic control of the Na–K balance in red cells.
Flowering and Morphogenesis of Kalanchoe in Response to Quality and Intensity of Night Interruption Light