The mitotic response of the stratified squamous epithelium at the edge of large perforations of the tympanic membrane in guinea-pigs.

Large perforations of the tympanic membrane were made in groups of guinea-pigs. The mitotic response in the stratified squamous epithelium at the edge of the wound was examined in perforations between 1 and 28 days after injury. Peaks of activity were discovered at 2, 15-16 and 24 days after wounding. It was also found that the maximal proliferative response was not at the immediate wound edge, as is usually maintained, but as some 2 mm from the wound edge. The results correspond remarkably well with work previously done by the present author on wounded rectal mucous membrane. The results are examined in the light of the chalone hypothesis of mitotic control.