AGE, DEATH AND CONJUGATION 563 



AGE, DEATH AND CONJUGATION^ IN THE LIGHT OF WOEK 



ON LOWER ORGANISMS^ 



By Professor H. S. JENNINGS 



THE JOHNS HOPKINS UNIVERSITY 



TTTNEOETUNATELY we are all interested in the subject of age 

 ^ and death. But the interest is of the kind that my friend Pro- 

 fessor 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 

 iguorance 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 organism,s, 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- 



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



