The following case speaks for itself. A young woman, twenty-eight years old, of a spare and apparently healthy habit, suffered almost continuously from pain across the lower part of the spine; the pain, as a rule, was dull, but sometimes it became acute; stooping was so painful that she found it as a rule almost impossible to pick up any object from, the ground. Upon examination the whole spine below the middle of the dorsal region was stiff when she bent; there was neither deformity nor tenderness, but the erectores spinae were very hard. The stammering test could not be applied as the pain on stooping was too great to allow the necessary attitude to be maintained for a sufficiently long time. On examining the abdomen the recti were rather rigid, and at first resented handling. A little gentle manipulative massage, however, led to their relaxation, and on the right side a distinct mass could be felt, which suddenly slipped away in the characteristic manner of a movable kidney. This was followed by a sense of relief like that which was usually felt when sudden or rapid modification in the symptoms happened. It therefore seemed pretty clear that the whole trouble might be due to a movable kidney which was prevented from returning to its normal site by some band or constriction after it had become displaced. At all events the probability of this view being correct was strong enough to justify the recommendation of an operation to fix the kidney. This was accordingly done, with the result that no further spinal symptoms had occurred up to the time when she was last seen - three years after the operation.