Further, breathing through the mouth has a tendency to induce inflammation in the tonsils and in the air passage connecting with the ear. This inflammation develops into those growths known as adenoids, which, when enlarged sufficiently, close the nostril entirely and prevent its normal use. A recent examination made by the New York Board of Health of 150 school children, all in some way abnormal, showed that 137 had either adenoids or enlarged tonsils. Example after example could be given of school boys and girls whose mental and moral development has been markedly retarded because of mouth breathing. One need only look at a child or adult who constantly keeps his or her mouth open to be impressed by the listless, vacant, inert appearance of the face thus disfigured. Figure 74 shows a photograph of a schoolgirl just before an operation and the characteristic expression due to adenoids is plainly marked. Earache is largely due to adenoids or to inflammation that rapidly leads to adenoids, and Mr. William H. Allen, Secretary of the Bureau of the New York Municipal Research, reports that in 415 villages of New York State, 12 per cent of the children living there were found to be mouth breathers. Whenever a child is unable to breathe through his nose, is slow in talking, and then speaks with a stuffy accent, calls "nose" "dose," has a narrow upper jaw, and is either deaf or has inflamed eyes, it is practically certain that enlarged tonsils and a well-developed growth of adenoids are present and should be removed. Not merely do these growths interfere with the mental and physical development of the child, but they also make him more susceptible to contagious diseases, particularly those of the lungs and bronchial tubes. [Illustration: FIG. 74.--Schoolgirl with adenoids.] The removal of adenoids is a simple operation, lasting not over a minute, and the result of the operation is in some cases almost miraculous. The medical inspectors of the New York City schools consider the removal of adenoids as a most important part of their work, and groups of children are regularly taken from the schools by the principal to the clinic at the hospital, where one after another tonsils are cut off or adenoids are removed, all fright and commotion being avoided by the gift of five cents as a reward. _Eyes._ Another evidence of advancing knowledge in matters pertaining to sanitary hygiene is shown in the greater attention given to the eyes, particularly of children. Such incidental troubles as headache, sleeplessness, or biliousness are frequently due to weak or strained eyes, and in the case of school children a great deal of the alleged insubordination, backwardness, and truancy of the children is caused by their being unable to see written instructions or explanations.