50 EX VIRIBUS VIVIMUS. 



9. Why Longevity is thus influenced. 



Before proceeding to do this — the propositions 

 standing thus : ' The potential longevity of a species 

 is favoured by high individuation and by small 

 expenditure, both generative and personal, and is 

 antagonized by small individuation and by great 

 expenditure, either generative or personal,' we might 

 ask why is it that this agreement of long duration 

 of life with high evolution and antagonism to ex- 

 penditure has been instituted or has arisen in the 

 slow development of ages ? If we can see what 

 purpose the Creator may have designed to serve 

 by such a disposition, or by what antecedent ne- 

 cessities He has caused it to arise, greater prob- 

 ability of truth will have been deductively added 

 to the conclusions. 



The amount of a species must be directly pro- 

 portionate to the amount of its accessible food. 

 It is on this fundamental relation that the argu- 

 ment rests. If the relations above shewn assist in 

 adjusting the amount of the species to the amount 

 of its accessible food, we can understand their 

 purpose, or how they must have arisen. Without 

 going into detail as to other terms introduced in 

 the argument, we may briefly endeavour to shew 

 how such an adjustment is favoured. The argu- 

 ment is developed at length for the quantities. 

 Fertility, Genesis, Individuation, Nutrition, in Mr. 



