A boy, aged 1 year, seen by one of us (H. L.), Jan. 28, 1930, had been previously treated for anorexia, vomiting, constant crying and inability to gain weight. The suggestion was made that the child was a hydrolabile baby (Finkelstein), gaining rapidly and losing rapidly without any acute alimentary disturbance to account for it. An explanation of this may be found in the hydronephrosis as revealed at autopsy, although this as a cause of the unstable weight was not suggested during life.
The child's weight was 16 pounds 3 ounces (7 Kg.). The size of the abdomen was striking but examination yielded no satisfactory results at that time. Four weeks later the child weighed 17 pounds 13 ounces (7.8 Kg.). The child began to sleep poorly and commenced to cry often. A specimen of urine obtained showed a large amount of pus. The child's abdomen was then examined under