Malpighian layer (stratum germinativum) The innermost layer of the epidermis of mammalian skin, separated from the underlying dermis by a fibrous basement membrane. It is only in this layer of the epidermis that active cell division (mitosis) occurs. As the cells produced by these divisions age and mature, they migrate upwards through the layers of the epidermis to replace the cells being continuously worn away at the surface.

Malpighian layer n. the stratum germinativum: one of the layers of the epidermis.