1. The daily administration to dogs of ten milligrams of cortisone per kilogram of body weight inhibited excessive formation of peritendinous fibrous tissue.
2. Cortisone administered during the waiting period prior to the delayed suture made approximation of the tendon ends easier than in the control group.
3. The administration of cortisone to dogs in which tendons had been severed and resutured did not prevent end-to-end healing of the tendons.
4. Regeneration of the tendon sheath was delayed during the administration of cortisone.
5. The breaking point of a sutured tendon treated with cortisone was consistently less than in the control tendons. Although the tendons treated with cortisone were 40 per cent. weaker than the controls, healing in both was adequate for function.
6. Gelfilm and gelfoam used locally diminished the peritendinous adhesions during healign of sutured tendons in dogs.
7. Pyromen administered intravenously to dogs diminished the quantity of fibrous tissue around healing tendons.