Scientia Sinica

126 SCIENTIA SINICA Vol, V

3. On the basis of our observations, new epidermal cells are formed from the development of the living substance.

(1) Material basis for the formation of new epidermis.

Academician Lepeshinskaya in the theory relating to the possibility of protoplasm developing into cells, writes, “In the protoplasm there should be all the components, necessary for the construction of the cell and its nucleus”. On the specimens we have clearly observed substances formed of difterent kinds of disintegrating tissues. These substances undoubtedly containing a large quantity of proteins, nuclear substance, lipoids etc. serve as the material basis for the formation of living substance and its subsequent development into cells. .

On the specimens we have observed that there are formless masses of aggregates containing remmants of leucocytes, collagenous fibres, and macrophages not yet completely decomposed. These formless masses are developed from the accumulation of the disintegrating substances; in other words, they are substances from the disintegrated tissues in the region of the wound and capable of development, hence the living substance.

These substances, as described by Academician Lepeshinskaya in her book, Life and Origin of the Cell,“ . . . . are protoplasm isolated from the cells of organism by mechanical destruction; under favorable conditions it acquires characters foreign to its own organization, and develops into another form, the cell.”%! Again she writes in the Life Process in the Pre-cell Stage: “The multiplication of cells in the process of wound-healing is not only by means of cell division or migration of cells along the blood vessels, but also by means of neo-formation from living substance, in form of small granules observed during destruction and disintegration of cells.”

(2) The developmental process of the epidermal cells.

On the basis of the facts observed from specimens, the process of new formation of epidermal cells can be summed up into the following stages:

1. In the wound the connective tissue elements, such as leucocytes, collagenous fibres, macrophages, cartilage, etc. are under destruction and disintegration and form the living substance.

2. The living substance develops along the margin of the epidermis. Morphologically it passes through different stages of development, such as the stages of formless masses aggregates, young cell nuclei, and young cells. Needless to say, there are complicated bio-chemical processes and physiological regulations from the organism taking place at the same time with the morphological changes, but they are beyond the scope of the present investigation.

3. Finally, it develops into newly formed epidermal cells. After the epidermal cells formed through the development from the living substance,