Every man is more or less the arbiter of his own fate. Granted that he has good tissue to begin life, his own habits and actions determine his span of comfortable existence. No one cares to live after his brain begins to fail, and the failing brain is often due to disease of the cranial arteries. The hygienic treatment resolves itself into advice in regard to prophylaxis. First and foremost is exercise. It has seemed to us that the revival of out-of-door sports is one of the best signs of promise of the preservation of a virile, hardy race. That women, as well as men, indulge in the lighter forms of out-of-door exercise should bring it about that the coming generation will start in life under the most advantageous conditions of bodily resistance. Among all the forms of exercise, golf probably is the best. It is not too violent for the middle-aged man, yet it gives the young athlete quite enough exercise to tire him. It is played in the open. One is compelled to walk up and down in pleasant company, for golf is essentially a companionable game, while he reaps the full benefit of the invigorating exercise. The blood courses through the muscles and lungs more rapidly; the contraction of the skeletal muscles serves to compress the veins and so to aid the return of blood to the heart: the lungs are rendered hyperemic, deeper and fuller breaths must be taken; oxidation is necessarily more rapid, and effete products, which if not completely oxidized would possibly act as vasoconstrictors, are oxidized to harmless products and eliminated without irritating the excretory organs. Other forms of out-door exercise that can be recommended are tennis, canoeing, rowing, fishing, horseback riding, swimming, etc. Tennis is the most violent of all the sports mentioned and might readily be overdone. Rowing as practiced by the eights at college is undoubtedly too violent a form of exercise, and may be productive in later life of very grave results. Canoeing is a delightful and invigorating exercise. The muscles of the arms, shoulders, and trunk are especially used, the leg muscles scarcely at all. Nevertheless, the deep breathing that necessarily comes with all chest exercises aerates every portion of the lungs, and is of great benefit to the whole body. Swimming as an exercise has much to recommend it. In this sport all the muscles take part and at the same time the chest is broadened and deepened. All these methods of using the muscles to keep oneself in trim, so to speak, are part and parcel of the general hygienic mode of life that is conducive to a healthy old age. Exercise can be overdone, as eating can be overdone. Both are essential and yet both can be the means of hastening an individual to a premature grave.