Hence on both counts it comes as a surprise to find two well-authenticated cases of crippled birds, unable to search for food for themselves, surviving for long periods. The first is T. R. Peale's record in 1848 of a brown booby on Enderby Island in the Pacific. An adult bird whose plumage indicated it was several years old was found on the island, and it had only one wing, the other having been lost by some accident and the wound completely healed. The bird was unable to go to sea and get its own food, and was being fed by its fellows. The second was a frigate bird, found on the Revillagigedo Islands, reported by A. W. Anthony in 1898. This bird, too, was fat, and had one wing withered and useless, evidently from hatching. It had never flown. Frigate birds are masters of the air that snatch their food on the wing from the surface of the water, and a flightless frigate bird would be as badly off as a flightless swallow. The cripple had been fed all its life by its neighbors. At first the uncritical might think, What altruism, what charity, for the healthy to feed these two cripples. But an explanation involving less advanced principles, principles more in keeping with what we know about bird behavior, is possible. Remember that young birds that are unable to begin feeding themselves at the proper time may continue to beg for food, and be dependent for a long time, as I have shown with young shrikes under the chapter, "Conditioning in Birds." Remember that a young bird begging for food may be fed by adults, not its parents, and even by other young birds (shown in "Bird Helpers at Nesting Time"); and we have the clue. The cripples, hungry, begged for food; the healthy birds responded by feeding, as they might do to other begging young, and owing to the unusual circumstances both were continued. These certainly are cases where the unfit survived. Natural selection has not operated. But such cases are rare exceptions. DUST AND SNOW BATHING [Illustration] The taxidermist preparing a bird specimen for the museum sometimes has to deal with one whose plumage is soiled or stained. He may have to wash it with water. Then, to dry the plumage, fluff it, and help in arranging the plumage so it will lie smooth and natural, he may use a powder: corn meal, sawdust, plaster, or plaster and potato starch may be worked into the feathers, then dusted out again. It is interesting that birds themselves use and have used long before taxidermists a similar method of using dust in dressing their feathers, a fact that anyone who has watched domestic hens for any length of time must be aware.