70 FOOT-NOTES TO EVOLUTION. 



from generation to generation never occur. We do not 

 expect to find birds arising from a " flying-fish in the 

 air, whose scales are disparting into feathers." A flying- 

 fish is no more of the nature of a bird than any other fish 

 is. A cow will never give birth to a horse, nor a horse 

 to a cow. The slow operation of existing causes is the 

 central fact of organic evolution, as it is of the evolu- 

 tion of mountains and valleys. Seasons change as the 

 relations which produce them change. But midsummer 

 never gives way to midwinter in an instant. Nor does 

 the child in an instant become a man, though in some 

 periods of growth epoch-marking causes may make de- 

 velopment more rapid. Life is conservative. The law 

 of heredity is the expression of its conservatism. Life 

 changes slowly, but it must constantly change, and all 

 change is by necessity divergence. 



There is in Nature no single " law of progress," nor 

 is progress in any group a necessity regardless of con- 

 ditions. That which we call progress 

 No innate tend- restg simply on the surv i va l o f the better 

 ency toward , , , . , , . 



progression. adapted, their survival being accom- 



panied by their reproduction. Those 

 that live repeat themselves. The " innate tendency 

 toward progression " of the early evolutionists is a 

 philosophic myth. Progress and degeneration are alike 

 the resultants of the various forces at work from gen- 

 eration to generation on and within a race or species. 

 The same forces which bring progress to a group under 

 one set of conditions will bring degradation under 

 another. In their essence the factors of evolution are 

 no more laws of progress than the attraction of gravita- 

 tion is. Cosmic order comes from gravitation. Or- 

 ganic order comes from the factors of evolution. Evo- 

 lution is simply orderly change. 



Nor is evolution identical with the notion of sponta- 



