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T is a fact well recognized in biology that a functionless organ is not tolerated by nature. In the evolution of life, whenever any organic structure has fallen into disuse, it has forthwith come under the law of atrophy and elimination. Until this law of atrophy and elimination is satisfied, the useless organ is a drain upon the vitality of the organism as a whole. It gives no equivalent for the support it derives from the life of which it is a part. In other words, it is parasitic. As a parasitic organ, moreover, it not only uses up energy that should go to the other organs that have a vital function to perform, but it also tends to become diseased and thus to impair the health of the entire organism.

There are numerous illustrations in the human body of the disuse and atrophy of organs, as well as of the incomplete elimination and disease of such organs. Thus there are many muscular structures, such as those of the pinna, epicranius and the platysma myoides, that are at present functionless and far on the way to complete atrophy. These useless organs are comparatively harmless, though, in strict truth, they must be nourished at the expense of the rest of the organic life. There are other functionless organs, however, that are not so harmless. Such is the vermiform appendix, in man a useless and retrogressive structure, which is apt to become the seat of serious disease. Such also are various functionless ducts, as, for example, the parovarium, which frequently become the seats of tumors, more or less malignant and destructive of life.

All these useless and, in a sense, parasitic organs of the human body, which modern research in the fields of physical anthropology, anatomy and embryology has brought to light and explained, point to laws of development that have a profound significance for every department of effort in which the control and improvement of man's life is an object. These laws are already beginning to be recognized by scientific educators. It is seen that the education of the mind and of the body consists essentially in doing what nature has been doing throughout the biological ages—that is to say, producing favorable variations through adjusting individuals to a progressive environment, perpetuating and perfecting these variations as more efficient organs of life, and getting rid of outgrown and useless organs so that no energy may be diverted