A STUDY OF HUMAN SKIN GRAFTED UPON THE CHORIO-ALLANTOIS OF CHICK EMBRYOS.

Human skin grafted upon the chorio-allantoic membrane of chick embryos adheres and becomes nourished for as long as 10 days. Occasionally regrafts upon a second egg have succeeded and thus prolonged the vitality of the graft to 14 days. In successful experiments the epithelium of the chorio-allantois fuses with that of the graft, the collagen fibers of the corium interlace with those of the membrane after the separation or disappearance of the ectodermal layer, and the blood vessels of the chick anastomose, and unite by intervening pools of extravasated blood, with those of the graft. This vascular communication between the two tissues is largely responsible for the nourishment of the graft by affording a plasmatic circulation. Gradually there is a partial revascularization of the graft by an ingrowth of blood vessels from the chick membrane. Human skin grafts were susceptible to experimental infection by several viruses.