Page:Popular Science Monthly Volume 53.djvu/201

Rh the resisting power of these beasts. Doubtless, many of the remains were ancient, for with the dry climate the decomposition of bone is a slow process; and there are no, or but few, hyenas to do away with the skeletons. The many parts lying about, therefore, hardly give a true value of the casualties of the travelers, inasmuch as they represent an accumulation of disaster reaching probably far back in years. But, such as they are, they are a grim and ghastly spectacle, and one not tending to give cheerful reflections to a leader of a caravan or to his hosts.



HEN we read in the daily newspapers of the collapse of a celebrated athlete, or the breaking down during training of a young aspirant for arenic honors, we naturally surmise that fundamental knowledge of the physiology of the muscular mechanism of the human body is either submerged by the overpowering desire to make a record, or totally absent, among certain trainers and their pupils. The want of such knowledge is the cause of many sad conditions existing to-day among former strong and healthy individuals. A comprehensive idea of the physiology of growth, of the physiologic and chemic relations of strength and endurance to age and condition, would be of great value to the present horde of senile individuals—not senile in years, but senile in vessels and tissues—who strive to make their century runs, as well as to the adolescent whose central nervous system is often permanently injured by overexertion in attempting to make the records placed by carefully trained and intelligent athletes.

The human body is a wonderful piece of mechanism, which not only renews itself constantly, but whose strength and endurance and capacity for more work increase with increased use up to the point at which use becomes abuse. At what time and under what pressure this danger line is reached depends upon the individual. However, the approach to this danger line is governed in all cases by fixed and immutable physiologic laws. The athlete must always bear in mind that the length of time that the muscle cell can continue to work will depend upon the rapidity with which the energy holding explosive compounds are formed by the cell protoplasm and the waste products are excreted (Howell). In other words, the