Cigarette smoking produces a flabby and endogenous condition of the optic nerve, and constant listening at a telephone, always with the same ear, decreases the power of the other ear till it finally just stands around drawing its salary, but actually refusing to hear anything. Carrying an eight-pound cane makes a man lopsided, and the muscular and nervous strain that is necessary to retain a single eyeglass in place and keep it out of the soup, year after year, draws the mental stimulus that should go to the thinker itself, until at last the mind wanders away and forgets to come back, or becomes atrophied, and the great mental strain incident to the work of pounding sand or coming in when it rains is more than it is equal to. Playing billiards, accompanied by the vicious habit of pounding on the floor with the butt of the cue ever and anon, produces at last optical illusions, phantasmagoria and visions of pink spiders with navy-blue abdomens. Base-ball is not alone highly injurious to the umpire, but it also induces crooked fingers, bone spavin and hives among habitual players. Jumping the rope induces heart disease. Poker is unduly sedentary in its nature. Bicycling is highly injurious, especially to skittish horses. Boating induces malaria. Lawn tennis can not be played in the house. Archery is apt to be injurious to those who stand around and watch the game, and pugilism is a relaxation that jars heavily on some natures. [Illustration: _Playing billiards, accompanied by the vicious habit of pounding on the floor with the butt of the cue ever and anon, produces at last optical illusions_ (Page 149)] Foot-ball produces what may be called the endogenous or ingrowing toenail, stringhalt and mania. Copenhagen induces a melancholy, and the game of bean bag is unduly exciting. Horse racing is too brief and transitory as an outdoor game, requiring weeks and months for preparation and lasting only long enough for a quick person to ejaculate "Scat!" The pitcher's arm is a new disease, the outgrowth of base-ball; the lawn-tennis elbow is another result of a popular open-air amusement, and it begins to look as though the coming American would hear with one overgrown telephonic ear, while the other will be rudimentary only. He will have an abnormal base-ball arm with a lawn-tennis elbow, a powerful foot-ball-kicking leg with the superior toe driven back into the palm of his foot. He will have a highly trained biceps muscle over his eye to retain his glass, and that eye will be trained to shoot a curved glance over a high hat and witness anything on the stage.