Urine concentrations were measured in samples from the ureter, the pel
vic cavity, close to the tip of the papilla, and from the most proxima
l part of the fornices of sheep kidneys, It was found that the concent
ration of urea, the osmolality, and the urine-to-plasma ratios of inul
in, urea and the osmolality were higher in the ureter than in the pelv
ic cavity. The same parameters were found to be higher in the pelvic c
avity than in the fornices except for the urea concentration which was
unchanged. The results of this study revealed the various concentrati
ons of urine in the ureter, the pelvic cavity and the proximal part of
fornices of sheep kidney.