Abstract 1. 1. In response to dehydration, the turtle, Chelodina longicollis, can increase the percentages of uric acid and ammonia in the urine and, at the same time, decrease the percentage of urea in the urine. 2. 2. The average rate of water loss from the skin and lungs was 1·18 mg per cent/day when the temperature ranged from 65 to 75°C and the relative humidity ranged from 60 to 70 per cent. 3. 3. Water can be reabsorbed from the bladder. 4. 4. Evidence for the presence of a salt gland in the orbit of the eye is given.