Page:Popular Science Monthly Volume 80.djvu/567

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By Professor H. S. JENNINGS


UNFORTUNATELY we are all interested in the subject of age and death. But the interest is of the kind that my friend Professor Lovejoy calls the interest of the repulsive. If we were free in the matter, we should doubtless prefer to neither hear nor know anything about the subject. But since to continue in that state of blissful ignorance and inexperience is impossible, we are driven to ask certain questions on the matter. What is the reason for our weakening and disappearing, along with all the visible living things that surround us? Why might we not as well continue indefinitely our interesting careers, instead of dropping off just as we become able to do something worth while? And must it be so inevitably? Is it grounded in the nature of life that all that live must die?

From the ancient seekers after the fountain of youth to the modern physiologists working toward the preservation of life, the prolongation of its processes, and the suppression of death, there have not lacked men who cherished the bold thought that death may be no essential part of life, that possibly some means may be found for counteracting the process of aging, for excluding death. And these men but express a secret wish of all mankind.

In this condition of affairs, a field of great interest was opened when the microscope revealed to us a world of organisms which seem at first view not to get old and die. As we follow them from generation to generation, the infusorian, the bacterium, seem not subject to the law of mortality. These creatures live for a time, then divide into two, and continue to live. Death appears, as we watch them, to occupy no place in their life history, save in consequence of accident.

This seemed to settle one of the great questions: whether age and death are inherent in life; inseparable from it. Here apparently was life without death; here was perpetual youth. If this can be in the infusorian, why not in other organisms, why not in man? Or if our thoughts be not so bold as this, may we not by study of the infusorian at least satisfy to a certain degree our understanding, learn perhaps something of the origin, cause and nature of age and death, and of the nature of that kind of life which avoids it? It is because I have de-

  1. A lecture before the Harvey Society of New York, March 3, 1912.