Abstract
1. Previous observations on the calcium and phosphorus metabolism of the pullet are confirmed.2. Calcium and phosphorus retention are shown to be related to the amount of sodium chloride in the food.3. The extra phosphorus excretion which accompanies egg laying involves no marked concomitant change of the amount of potassium in the droppings. Small concomitant increases in the sodium in the droppings were observed where the food contained only small amounts of sodium and chloride; potassium retention was observed on the succeeding day in every case but one.