THE CYCLE OF LIFE 437 



Queries at the time when Sir G. C. Lewis's wholesome 

 scepticism created much stir. As man is a slowly varying 

 organism, as regards physical characters at least, it is 

 extremely unhkely that his longevity was ever much greater 

 than it is now. Monsters in age and monsters in size are 

 ahke increditle. 



A fact of much interest is the statistical evidence 

 that such a subtle character as ' longevity ', that is to 

 say, a tendency to a certain lease of hfe, be it long or short, 

 is heritable hke other inborn characters, though it rests 

 of course to some extent with the individual or his environ- 

 ment to determine whether the inherited tendency is 

 reahzed or not. Just as stature is a heritable quahty, so is 

 potential longevity, but the degree of expression is in part 

 determined by ' nurture ' in the widest sense. 



Professor E. Metchnikoff is one of the few modern biolo- 

 gists who would deal generously with bibhcal and other old 

 records of great human longevity. He apparently thinks 

 there has been some misunderstanding in regard to Methu- 

 saleh's 969 years or Noah's 595, but he accepts the great 

 ages of 175, 180, and 147 years ascribed to Abraham, Isaac, 

 and Jacob. Similarly, he accepts the 185 years with which 

 St. Mungo of Glasgow has been credited. And as he is 

 generous in regard to the past, he is hopeful in regard to the 

 future, beheving that a more careful and temperate life, 

 as well as an enhghtened recognition of the disharmonies of 

 our bodily frame, may bring about a time when man will 

 no longer, as Buffon said, die of disappointment, but 

 attain everywhere a hundred years. ' Humanity ', 

 Metchnikofi says, ' would make a great stride towards 

 longevity could it put an end to syphiUs, which is the cause 

 of one-fifth of the cases of arterial sclerosis. The sup- 



