Magnified section of scalp, historical artwork. The external surface is the cuticle, with the layer of skin below this known as the rete mucosum, or epidermis. Deeper in is the living layer, known as the dermis, consisting of the papillary layer and corium. Deeper still is the subcutaneous fatty layer (yellow, bottom). The hair shafts are flanked by sebaceous follicles (yellow), and emerge from sudoriferous follicles. From The Nerves of the Human Body (1839).