HUMAN LONGEVITY. 109 



and assuming the average period of growth in height in Man 

 to be about sixteen years, he takes six or seven periods, the 

 multiples of this time, to express the natural duration of 

 human life. He fortifies himself in this result, by noting a 

 certain proportion of time of growth to the length of life in 

 other animals, as the horse, dog, stag, &c. ; but neither 

 numerically nor otherwise does he claim for his doctrine the 

 absolute exactness of a physical law. ' The whole duration 

 of life may in some measure be calculated by that of the 

 period of growth. Man, who is fifteen years in growth, may 

 live six or seven times that period of time.' 



M. Flourens is bolder in his conclusions, and in the same 

 degree farther removed from truth. He adopts as the term 

 or limit of bodily growth (accroissement) the complete union 

 of bones at their Epiphyses (an expression we shall speedily 

 explain), and alleging this consummation of growth to 

 occur in man at the age of twenty ; and in certain other 

 animals at other ages, but in each respectively the fifth part 

 of the term of life, he at once multiplies by 5 the 20 years of 

 human growth, and pronounces 100 years to be the natural 

 period of human existence. We produce this view in his 

 own words : 



Buffon says that every animal lives about six or seven times as 

 long as it is in growing. On this supposition the relation would be 

 as 1 to 6 or 7 ; but the real relation of the period of growth to the 

 duration of life is as 1 to 5, or nearly so. Man is 20 years growing, 

 and he lives five times 20 years, or to 100. The camel is 8 years 

 growing, and he lives to 40 : the horse 5 years growing, and he lives 

 to 25 ; and so on to other animals. We have thus then, at last, 

 an accurate criterion which gives us with certainty the period of 

 growth. The duration of that period gives us the duration of life. 



The argument, thus put, is more summary in manner 

 than satisfactory in substance. We doubt much whether this 

 period of epiphysis, or completion of bony union, has been 



