Scientia Sinica

No. 1 MA: FORMATION OF NEW EPIDERMAL CELLS DURING WOUND-HEALING 121

Arey", Patten!) Jordan and Kindred™!, etc. in embryology; Cowdry™!, Maximow and Bloom®!, Bailey!!,Bremer!, Schafer™!, Jordan”!, Lamber"”!, Ham"), etc. in histology; Ormsley!”!, Sutton and Sutton!”!, etc. in dermatological pathology; McCarthy'™!, Lewer'®!, etc. in dermatological histo-pathology.

In a paper reveiwing the healing of wound, Arey in 1936, quoted from more than three hundred and sixty papers in literature. All those papers cited and his own review accept that the new epidermal cells come from original epidermis, or epithelium of the hair follicles.

Ham! writes in his new textbook of histology that during the healing of the burn the new epidermal cells come from hair follicles and sweat glands, but he does not mention how they are formed.

Gordon, Hall, Heggie and Horne'"*! give the same description. They claim that chains of new cells come from the hair follicles and sweat glands to the surface, and as soon as they reach the surface of the wound they spread out into a thin layer of cellular membrane and later they develop into cells of stratified epidermis. They find no case of any cell in the conditions of mitosis, but arround the hair follicles they claim that they find cells in mitotic division. They describe isolated groups of epidermal cells as without any connection with the epidermis, but they consider that such groups come from cells of the hair follicles or sweat glands which do not undergo necrosis. They have not mentioned whether there is any mitotic figure in the nonnecrotic hair follicles or sweat glands.

All the above-mentioned authors consider the new epidermal cells to be generated from the pre-existing epidermis or its appendages, hair follicles or sweat glands.

Investigators in the past, under the influence of the traditional cell theory,

used to try various reasons to accommodate instead of questioning the soundness of the theory, whenever they came to any discrepancy in their research work. Those traditional concepts are hindrances to the progress of science. For instance, many investigators have found out in their experiments that the number of epidermal cells produced by means of mitosis is far below the number required to supply the loss of cells due to desquamation. But in order to suit the old theory, the following debatable explanations have been given.

(2) Thuringer'”! observed the scantiness of mitosis on the specimen of human epidermis. He concluded that new epidermal cells produced by mitosis could not replace the loss due to desquamation. He observed binucleated cells under the stratum granulosa, and considered that the supply of new epidermal cells was not only from mitosis but also from amitosis.

In his work on epidermis, Patzelt'’! argues that it is impossible to consider mitosis as the only source of new cells to replenish the desquamating cells, for the number lost far exceeds that produced from mitosis. Therefore,