1. A series of cases of Morton's metatarsalgia is reported in which twenty-seven selected patients have had thirty-five operations on the sole of the foot.

2. At operation, degeneration of the plantar digital artery to the cleft between the third and fourth toes has now been found to precede the fibrous thickening of the nerve described by Betts in 1940. Similar changes rarely occur in neighbouring clefts.

3. Local resection of the nerve almost always gives complete relief from pain, and the plantar scar gives rise to no trouble.

4. Histological findings show that the nerve lesion is ischaemic in nature.

5. Acute pain arising as a new event in cases of the deformity of "anterior flat foot" may prove to be due to this condition.

6. Morton's metatarsalgia is a distinct clinical and pathological entity which can best be described as a plantar digital neuritis.