EVOLUTION DEFINED 7 



known to science. We can recognize no logical necessity until 

 we are in possession of all the facts. No ultimate fact is yet 

 known to science. 



For reasons indicated above the term evolution is not 

 wholly acceptable as the name of a branch of science. The 

 term bionomics is a better designation of the changing of 

 organisms influenced through unchanging laws. It is a name 

 broader and more definite than the term organic evolution, it 

 is more euphonious than any phrase meaning life adaptation, it 

 involves and suggests no theory as to the origin of the phenom- 

 ena it describes. 



It is a matter of common observation that organisms change 

 from day to day, and that day by day some alteration in their 

 environment is produced. It is a conclusion from scientific 

 investigation that these changes are greater than they appear. 

 Not only do they affect the individual animal or plant, but they 

 affect all groups of living things, classes or races or species. 

 No character is permanent, no trait of life without change; 

 and as the living organism and groups of organisms are un- 

 dergoing alteration, so does change take place in the objects 

 of the physical world about them. "Nothing endures," says 

 Huxley, "save the flow of energy and the rational order that 

 pervades it." The structures and objects change their forms 

 and relations, and to forms and relations once abandoned they 

 never return; but the methods of change are, so far as we can 

 see, immutable. The laws of life, the laws of death, and the 

 laws of matter never change. If the invisible forces which 

 rule all visible things are themselves subject to modification 

 and evolution we have not detected it. If these vary, their 

 aberrations are so fine as to defy human observation and com- 

 putation. In the control of the universe we find no trace of 

 "variableness nor shadow of turning." 



But the objects we know do not endure. Only the shortness 

 of human life allows us to speak of species or even of individuals 

 as permanent entities. The mountain chain is no more nearly 

 eternal than the drift of sand. It endures beyond the period of 

 human observation; it antedates and outlasts human history. 

 So may the species of animal or plant outlast and antedate the 

 lifetime of one man. Its changes are slight even in the lifetime 

 of the race. Thus the species, through the persistence of its 

 type among its changing individuals, has come to be regarded 



