1. Sixty-nine additional specimens of Dupuytren's contracture have been studied. These specimens were fixed with the fascia under normal tension and sectioned longitudinally.

2. The lesion of Dupuytren's contracture begins as an area of fibrous-tissue proliferation and ends as a band of thick collagen fibers. Hemosiderin deposits in the cellular areas are believed to be evidence of previous hemorrhage into the areas. Abrupt termination of collagen fibers at the edge of the cellular nodules has been observed.

3. Partial rupture of the palmar and plantar fascia was produced in twelve monkeys, together with appropriate control operations. By this method a lesion which resembles the cellular stages of Dupuytren's contracture has been produced. The monkey lesion matures into dense collagenous tissue in the same way that the cellular stages of Dupuytren's contracture mature. Contracture of the finger did not develop in the monkeys in these experiments.

4. One patient has been encountered in whom a nodule developed within the palmar fascia after laceration of the fascia. The nodule had the microscopic characteristics of the cellular stage of Dupuytren's contracture.

5. A similar fibrous-tissue proliferation has been provoked by partial rupture of the anterior rectus sheath of a dog. The response in the dog was less intense than in the monkey and the lesion healed more rapidly.

6. These observations lead us to believe that partial rupture of the palmar aponeurosis is one way in which the type of fibrous-tissue proliferation observed in Dupuytren's contracture can be provoked.