1. On the basis of, first, a mathematical analysis of the age-specific and sex-specific prevalence of Dupuytren's contracture; second, the genetical aspects; and last, the pathology, it is concluded that Dupuytren's contracture is probably a spontaneous disturbed-tolerance auto-immune disease.

2. The proportion of predisposed individuals at birth is about 20 per cent of males and females in the population studied by Early (1962), although it differs between populations and races.

3. The disease is probably initiated by four random, dependent-type, autosomal somatic gene mutations in a stem cell of the lymphoid system. With the accumulation of the fourth and final somatic mutation, a "forbidden-clone" of lymphocytes is probably generated. There is a latent period between the occurrence of the last initiating event and diagnosis.

4. In men the average latent period is about fifteen years, in women it is about thirty years.

5. The target tissue primarily attacked by forbidden lymphocytes is unknown, although proliferating fibroblasts are evidently a consequence of the auto-immune attack.