Not only are our hairs numbered, but each particular hair is furnished with a little individual muscle of its own running from the base of the follicle to the inner surface of the true skin, so that when the proper occasion arises for erection of that individual hair the muscle contracts apparently of its own accord, and up stands the hair along with its fellows, ready to frighten the animal that dares to approach in hostile attitude the owner of the precious coat. Similar muscles erect the feathers of the owl, and the gorgeous tail of the peacock dazzles us in the sunlight moved in like manner, while to those more powerful dermal appendages, the claws, talons, and nails, are attached more powerful muscles still, with proper nerve connections for the most effective use of the weapons nature has formed out of the soft outer skin, which is usually so mild and yielding as to have earned the name of scarf skin. This outer skin is formed of cells, flat on the surface, but near the true skin where they originate, rounded and in many cases even tall and apparently reaching out towards the surface. It gives the color to the person by means of pigment cells which lie in its midst. The black man is dark because of the abundance of pigment cells in his scarf skin. The albino is light because of their absence. The colors of hair and feathers are due to these cells in their receptacles, but white and iridescent feathers are doubtless so partly because of their absence and partly because of hollow spaces which catch and reflect or refract the light. This arrangement of cells into scarf skin has much to do with the healing of wounds. In cases of old sores that refuse to heal, or where the skin has been extensively destroyed, the doctors have found that good, healthy skin may be grafted upon the sores in such a manner as to invigorate and perfect the process of healing. Small particles of fresh skin taken from a healthy subject or from some other part of the patient's body are placed upon the sore, the portions used being about the size of a small pinhead, and new life seems transplanted in the deadened part. The skin of a black man grafted upon that of a white man shows afterwards no trace of its origin, but becomes the same shade as that which it adjoins.