We must go back to the time, however, when man walked on fours, for that is probably the real explanation. Originally man’s fingers were of different lengths because all four-footed animals had the same peculiarities. The shape and length of the toes and their arrangement were the ideal arrangement for giving the proper balance and support to the body, and in moving about and in climbing produced the best toe hold. Why Does It Hurt When I Cut My Finger? It hurts when you cut your finger, or, rather, where you cut it, because the place you have cut is exposed to the oxygen in the air, and as soon as it is so exposed a chemical action begins to take place, just as when you cut an apple and lay it aside you come back and find the cut surface all turned brown. If the apple could feel it would hurt also, because the chemical action is much the same. The apple has a skin which protects its inside from the oxygen in the air, and you have also a skin which protects you from the oxygen as long as it is unbroken. What happens, of course, is this: When you cut your finger you sever the tiny little veins and nerves which are in your finger. They are spread all over your body like a net-work under the skin, close to the surface in most places. The nerves when cut send a quick message to the brain, with which they are connected, telling that they are damaged, and the brain calls on the heart and other functions to get busy and repair the damage along the line. There may be some hurt while this process of repairing is going on, but the principal part of your hurt, outside of what we call your feelings, is due to the fact that the inside of you is thus exposed to the chemical action of the air. Then I can hear you say next: Why Don’t My Hair Hurt When It Is Being Cut? It does not hurt to cut anything that has no nerves. There are no nerves in the hair which the barber cuts. If he pulls out a hair it hurts, because the root of the hair has nerves, which telegraph notice of the damage to the brain. When a dentist takes out or kills the nerve in your tooth you cannot have any more toothache in that tooth, because there is no nerve there to send the message to the brain. You can cut your finger nails without feeling pain, because they have no nerves at the ends, but underneath, where they join the skin of the finger, there are a great many nerves, and it hurts very much to bruise the nails at that location. Of What Use Is My Hair? ~WHY WE HAVE HAIR~