The accompanying illustration shows an interesting case of polydactylism. The patient is a white woman, 35 years of age. She says that, so far as she knows, there is no history of polydactylism in her family. She has five children, all of whom are normal in this respect.
The supernumerary thumb here shown is well developed and shows a well-defined metacarpo-phalangeal joint, which is capable of flexion and extension to a slight degree. The phalangeal joint is also well defined and exhibits some degree of flexion and extension.
A supernumerary thumb on the other hand was stitched to the normal thumb in infancy, and the result of the union presents the appearance of a very wide thumb with a single wide nail.