This work confirms that foetal wound healing is rapid, occurs without an apparent inflammatory response and takes place without the deposition of collagen. It is shown for the first time that foetal muscle wounds heal by regeneration. This study also shows that, immediately after injury, there is a degeneration of mesenchymal and ectodermal elements in that part of the lip between the wound and the mid line. This degeneration is followed by regeneration of only the mesenchymal elements.