Two groups of experiments were carried out on the profundus tendons of New Zealand rabbits: 1. Simple closed tenotomies at various levels along the digit. 2. Open tendon division followed by repair with a Bunnell criss-cross suture. At intervals after the operation injection studies were performed to outline the vascular pattern within the tendons. The results indicate that the circulation through the intratendinous vessels is precarious and it may be impaired both by tenotomy and by the presence of sutures. It is suggested that this may be an important factor in the pathogenesis of adhesions. The clinical implications are discussed.