In mammalian skin, the Malpighian layer is the innermost layer of the epidermis. It is separated from the dermis by a fibrous basement membrane. The Malpighian layer is the site of active cell division. Some of the new cells thus formed leave the layer, become keratinized, and replace the outer cells of the epidermis which are continually worn away. The Malpighian layer also contains most of the melanin responsible for dark skin. It is named after the Italian anatomist Marcello Malpighi.