I. The interaction between nitrogen and water intake was studied in two ewes and two red deer hinds. They were given pelleted diets, at maintenance level, containing equal amounts of roughage but either rich or poor in nitrogen. The deer received 5 0 yo more food than the sheep. Water was given either in large amounts (sheep 5.0 1, deer 7.0 1 daily) or in small amounts (sheep 1.1 1, deer 2.4 1 ...