MOTHER: And we see how the eyes are kept from in´ju-ry, too, by the little porches, or eyebrows, above. The stiff hairs, like a hairy arch, keep the sweat from running into them, and they also add beauty to the face. Then there is a pair of curtains for each one. AMY: I know what they are,--the eyelids. MOTHER: And like a double curtain, or shutter, they close to keep the eyes from harm whenever danger is near. Quick as thought they shut tightly together; and each one has a hairy fringe to keep out dust or other objects hurtful to the eyes. Each of these curtains, or awnings, is placed in charge of two servant muscles, one to raise, the other to lower it, and they play up and down without noise or a hitch anywhere. HELEN: And when we go to sleep, they softly close the window until we wake again. [Illustration: An eye] MOTHER: These windows in our house also wash and keep themselves clean. There is a tiny factory above the eye, where tears are made. Perhaps you have often wondered where tears came from, and now you know. As the eyelids move up and down, the tears keep running over the eye, which makes it move so easily in the socket that it does not ache or wear out, and they keep it clean and bright. There is a little drain-pipe opening on the inner side of each lower eyelid, which carries away the tears into the nose after they are used. If we are sad or unhappy, sometimes so many tears are made that they can not pass through these drains, and then they run over the eyelids down the cheeks. There are also some little factories in the eyelids which make an oil for the edges of the lids, so they will not stick together, and to keep the tears from running over the face. [Illustration: _This little boy’s tears have “come unfastened.”_] PERCY: I never knew before where the tears came from, and that they were being made and used all the time. HELEN: Nor I. Not long ago I read about a little girl named Margie who never cried when any small mishap came to her. But one day her best-loved dolly fell and got a dreadful bruise on her nose. Margie winked hard a few minutes, and then buried her face in her mother’s lap, sobbing, “O mama, I don’t _want_ to cry, but _all my tears have come unfastened!_” MOTHER: Poor child! she was nearer the truth than she thought; and no doubt many folks, big and little, would be glad sometimes if they could keep their tears fastened up better. Have you ever thought why your eyes do not fall out when you bend over? AMY: They must be fastened in tight. [Illustration: _Muscles of the eye._] MOTHER: That is true; for they are held by six little muscles, whose work it is to keep them in place and move them about. ELMER: But what is inside of the eye, mother?