300 THE INDUCTIONS OF BIOLOGY. 



been favourable or unfavourable to physical prosperity. The 

 established constitutional tendency, adapted to the needs of 

 the species, over-rides the constitutional needs of the indi- 

 vidual. 



Even here, however, the primitive antagonism, though 

 greatly obscured, occasionally shows itself. Instance the 

 fact that in plants where gamogenesis is commencing a sudden 

 access of nutrition will cause resumption of agamogenesis ; 

 and I suspect that an illustration may be found among 

 human beings in the earlier establishment of the reproduc- 

 tive function among the ill-fed poor than among the well-fed 

 rich. 



One other qualification has to be added. In plants and 

 animals which have become so definitely constituted that at 

 an approximately fixed stage, the proclivity towards the pro- 

 duction of new individuals becomes pronounced, it naturally 

 happens that good nutrition aids it. Surplus nutriment being 

 turned into the reproductive channel, the reproduction is 

 efficient in proportion as the surplus is great. Hence the 

 fact that in fruit trees which have reached the flowering stage, 

 manuring has the effect that though it does not increase the 

 quantity of blossoms it increases the quantity of fruit; and 

 hence the fact that well-fed and easy-living races of men are 

 prolific. 



