SummaryThe effects of scab formation and the nature of the wound bed on the contraction of wounds have been investigated. Rabbit paraffin gauze dressed flank wounds with the panniculus carnosus intact and rat paraffin gauze dressed full skin thickness back wounds had constant linear rates of movement of the wound margins throughout the lime of contraction. Rabbit undressed wounds with the panniculus carnosus retained or excised and rat undressed wounds showed phases of rapid movement, no movement and normal movement of the wound margins during the course of contraction. These were effects of scab formation, they were transient and had little or no effect on the overall rate of wound contraction. The behaviour of rabbit undressed wounds with the panniculus excised was similar to that of comparable wounds with the panniculus intact, except that healing was delayed by approximately 3 days. Very variable behaviour was observed with rabbit paraffin gauze dressed wounds with the panniculus excised.