The material of a feather consists of cells that push each other out to their destination. They change their forms as they travel along, and their colors and degrees of hardness change with their going. They are composed of about the same stuff that makes horns and hoofs. Your finger nail is like a feather in its growth and composition. It is mostly albumen with some lime in it. Albumen is the substance which makes the white of eggs. When the Mexican motmot trims his two tail feathers with his beak, he merely makes diamond cut diamond. The material of the cutting instrument is the same as that of the thing cut, only somewhat harder. When you consider how a feather grows by pushing out its cells you must wonder at the intelligence which guides the cells to change their nature so as to form the quill, the shaft, the after-shaft, the barb, the barbules, and the little hooks which hold them together. More than this is the cause for admiration seen in the regular change of pigment contained in the cells, so the feather shall have its beautiful colors and accurate markings. Along with the materials of the feather is carried a little oil which turns the water from the duck's back and gives the feather its gloss. It is thought by some that the fading of feathers in museums where mounted specimens are exposed to the action of light is largely due to the loss of this delicate oil. No enterprising Yankee has come forward yet with a patent for restoring this oil and giving back to the thousands of musty and dusty skins in our museums their original brilliancy. Every one wonders at the way feathers keep their shape instead of getting hopelessly ruffled. The little hooks which hold the barbules together are exceedingly strong and flexible. They will yield and bend, but never break. Even when torn apart from their hold they can grasp again so as to restore the injured feather to its former shape. VISION AND SCENT OF VULTURES. REV. R. T. NICHOL. _To the Editor of Birds and All Nature_: SIR: Are you not mistaken in the assertion in your October number that vultures, carrion-crows, etc., have such keen scent that they can detect carcasses and offal at a very great distance? I was under the impression that Wilson[1] had decided this forever, and proved conclusively that their apparently miraculous power of discovering their proper food, was due to keenness of vision, and not of the sense of smell. The following extracts may be new to some and interesting to all of your readers: Under the head "_Vultur aura_, Turkey Vulture," etc., I find: "Observations on the supposed power which vultures such as the turkey vulture, are said to possess of scenting carrion at a great distance.