B. C., a boy, aged 9 years, is healthy and normal in all respects except for the left upper extremity, which at first sight resembles very closely an intra-uterine amputation through the upper third of the forearm. The humerus is normal in size and function. There is normal range of motion at the elbow. The radius and ulna are palpable, and at their distal end is a small piece of bone, to which is attached a flexor and an extensor tendon. This small bone, evidently a rudimentary metacarpal bone, can be very easily flexed and extended. The stump is well shaped and padded.
The roengenograms show that the condition is not an intrauterine amputation, since both the radius and the ulna are practically perfectly formed, being only half or one third the normal length. There is complete absence of carpal and metacarpal bones, with the exception of the single rudimentary