NUTRITION AND GENESIS. 481 



tissue and the evolution of force; and this is the plethora 

 which we have found to be associated with unusual fecundity. 

 Abnormal plethora which, as truly alleged, is accompanied 

 by infecundity, is a superfluity of force-evolving materials 

 joined with either a positive or a relative deficiency of tissue- 

 forming materials : the increased bulk indicating this state, 

 being really the bulk of so much inert or dead matter. Note, 

 first, a few of the facts which show us that obesity implies 

 physiological impoverishment. 



Neither in brutes nor men does it ordinarily occur either 

 in youth or in that early maturity during which the vigour 

 is the greatest and the digestion the best: it does not 

 habitually accompany the highest power of taking up nutri- 

 tive materials. When fatness arises in the prime of life, 

 whether from peculiarity of food or other circumstance, it is 

 not the sign of an increased total vitality. On the contrary, 

 if great muscular action has to be gone through, the fat 

 must be got rid of; either, as in a man, by training, or as in 

 a horse that has grown bulky while out at grass, by putting 

 him on such more nutritive diet as oats. The frequency 



of senile fatness, both in domesticated creatures and in our- 

 selves, has a similar implication. Whether we consider the 

 smaller ability of those who display it to withstand large 

 demands on their powers, or whether we consider the com- 

 paratively-inferior digestion common among them, we see 

 that the increased size indicates, not an abundance of mate- 

 rials which the organism requires, but an abundance of 

 materials which it does not require. Of like meaning 



is the fact that women who have had several children, and 

 animals after they have gone on bearing young for some 

 time, frequently become fat; and lose their fecundity as 

 they do this. In such cases the fatness is not to be taken 

 as the cause of the infecundity; but the constitutional 

 exhaustion which the previous production of offspring has 

 left, shows itself at once in the failing fecundity and the 

 commencing fatness. There is yet another kind of evi- 



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