embryo wound healing SEM

A scanning electron micrograph of a healing wound on the surface of a chick embryo limb bud about one hour after wounding. The leading edge of the outer surface (epithelium) cells, shown by the curved line, forms a cable (made up of a protein called actinomyosin) which draws the epithelium over the underlying tissue to close the wound. In embryos wounds heal perfectly without a scar.