AN ESSA V ON LONGEVITY. 47 



not a sudden but a gradual acquisition of volume. 

 We infer that a great thickness of strata, or of other 

 such accumulations, has taken a long time to grow, 

 measuring the time by the bulk ; similarly, a large 

 population or a large city is known to take a long 

 time to accumulate. That complexity and interde- 

 pendence of structural arrangement also implies time 

 spent in the evolution of those arrangements, is proved 

 from the observation of other cases of non-organic 

 development. A language, a civilization, a city, a 

 land-surface, the sidereal system, are universally ad- 

 mitted to have taken time in their growth in pro- 

 portion to their complexity, in proportion to the 

 extent of redistribution and readjustment of parts 

 of which they bear tokens. And so we may infer 

 that high organic complexity and high organic bulk, 

 both involved in the term ' high evolution,' or better 

 perhaps 'high individuation,' postulate time in pro- 

 portion, and we may conclude that high individua- 

 tion favours longevity. 



8. Small Expenditure favours Longevity. 



We now come to a proposition which we have 

 already anticipated in previous paragraphs, and which 

 has great importance, qualifying largely as it does 

 the application of the preceding, and explaining the 

 reason of the existence of a normal potential lon- 

 gevity limited in some cases abruptly by natural 



