Normal and Abnormal Variation in the Dimensions of Pairs of Kidneys

SUMMARY 1. Study of kidney weights in post‐mortem material defined the limits of normal variation in weight between the members of pairs of healthy kidneys. 2. There is an almost identical variation in the areas of pairs of kidneys in normal pyelograms. 3. In a large series of pyelograms it was found that abnormally small kidneys were found more frequently on the right side than on the left. 4. This preponderance of contracted kidneys on the right side cannot be explained by hypo‐plasia, dysplasia or hypertensive vascular disease. 5. Post‐mortem weights of pairs of pyelonephritic kidneys show a disproportionate number of contracted kidneys on the right side.