Abstract
1. The behaviour and fate of skin autografts and skin homografts in guinea-pigs is described. 2. In general the homograft reaction in the guinea-pig resembles that of the rabbit, but the inflammatory changes that accompany breakdown are less pronounced. 3. The survival time of skin homografts transplanted between genetically diverse guinea-pigs ranged from 5 to 17 days in different individuals. 4. Skin homografts transplanted to guinea-pigs that had been immunized beforehand by grafts of skin from the same donor underwent accelerated breakdown. 5. The daily subcutaneous administration of 5 mg of cortisone acetate is ineffective in prolonging the life of skin homografts in guinea-pigs, but the daily subcutaneous injection of 25 mg of cortisone acetate at least doubles their survival time. 6. Daily intraperitoneal injections of as much as 20 mg of cortisone were ineffective in prolonging the life of skin homografts. The route of injection is therefore a significant variable. 7. Cortisone did not retard the healing of autografts or homografts. 8. The oral administration of extra ascorbic acid had no appreciable effect on the skin homograft reaction and did not improve the healing of grafts transplanted to guinea-pigs maintained on a diet of oats and hay with supplementary cabbage.