Heredity, Variation and Genius 7 



flux is pretty well restricted to the human line of 

 progress, man's dominant ascendency having made 

 a hostile environment which has stopped natural 

 progress in the lower animals, although not per- 

 haps in all the minutest forms of microbal life 

 which still fight him not unsuccessfully and may 

 conceivably one day be victorious. How can 

 variational shoots of parent stems, such as once 

 grew into different species of living things, take 

 effect now in face of a man-made environment, 

 uniformly adverse, which checks variation and 

 prevents differentiating adaptation ? In the 

 animal kingdom it has come practically to this — 

 that the lower animals are reduced to the self- 

 conservative instinct ; in man only does the per- 

 fective instinct work. He is, so to speak, the 

 supreme branch of the tree of life in which the 

 ascending sap yet stirs active growth, the present 

 and perhaps final culmination of organic develop- 

 ment on his planet ; which in truth may well be 

 the case, seeing how successfully he has absorbed 

 and exploited all lower organic being and what 

 small likelihood there is of the advent of higher 

 being to absorb and exploit him. 



Asking whence this force of organic evolution 

 is derived, the answer is simple enough if the 

 enquirer be content to stay in secondary causes. 

 It is plainly due to the innumerable minute and 

 perpetually beating pulses of the sun's rays upon 

 living protoplasm from its earliest and simplest 

 up to its latest and most complex development ; 



