UNDER THE APPLE-TREES 



less will be checked. The fuel in the earth will be 

 exhausted in a thousand or more years, and its min- 

 eral wealth, but man will find substitutes for these 

 in the winds, the waves, the sun's heat, and so forth. 



X. AN UNKNOWN FACTOR 



How this unknown factor in life, or the vague 

 consciousness of it, hovers in the backgroimd of 

 the minds of even the most rigid scientists! It hov- 

 ered in Darwin's mind when he said he could not 

 look upon man, with all his wonderful powers, as the 

 result of mere chance, though his theories of the 

 origin of species made man the result of fortuitous 

 variations conserved and improved upon by natural 

 selection. It hovered in Tyndall's mind when his 

 physicochemical theory of the origin of life left him 

 on the brink of an abyss, and he contemplated 

 "the mystery and miracle of vitality." It hovered 

 in Huxley's mind when he resented the charge of 

 materialism and gave consciousness a place with 

 matter and energy as one of the three realities in 

 the imiverse. It hovered in Haeckel's mind when he 

 admitted a psychic principle in the atom. Professor 

 Osborn finds some unknown and unknowable factor 

 in evolution from the fact that some parts or organs 

 are adaptive, or pm-poseful, from the first, and were 

 fitted to survive when they first appeared. 



THE END 



