Six domestic fowls were operated for exteriorization of the ureters.2. Three weeks after the operation their food and water intake was compared with that of six unoperated control fowls of similar weight.3. Water intake was calculated from the amount of water drunk, the metabolic water and the water content of the food eaten; while water loss was estimated from the water content of urine and faeces excreted and from evaporation.4. Fowls with exteriorized ureters drank more than the control birds. The excess of water drunk by these birds approximated the amount of water lost in the urine.