Abstract
1. By means of the Bielschowsky-Seto's method of neurofibril stain-ing, the author have concluded that the nevus cell is not the production of the “Abtropfung” of epidermis (Unna), but originates from the neuro-ectodermal cell which is homogenetic with the Schwann's cell of Masson.
2. I have recognized the argentaffinity of the Schwann's cell by Bielschowsky-Maresch's staining, and have supported the neurogenic nature of nevus cell. But I am obliged to regect the so-called Abtropfung theory on account of the indifferent attitude of argentaffin fibril against the epi-dermis.
3. The author believes the melanin production depends entirely upon the chemical reaction in the cell which is in contact with the termination of peripheral vegetable nerve, and that it does not matter whether the cell is ectodermal or mesodermal.
