PART IV 



THE EVOLUTION OF ANIMAL LIFE 

 CHAPTER XVII 



THE EVIDENCES OF EVOLUTION 



I. The Idea of Evolution — 2. Arguments for Evolution : Physio- 

 logical, Morphological, Historical — 3. Origin of Life 



We observe animals in their native haunts, and study their 

 growth, their maturity, their loves, their struggles, and their 

 death ; we collect, name, preserve, and classify them ; we 

 cut them to pieces, and know their organs, tissues, and 

 cells ; we go back upon their life and inquire into the secret 

 working of their vital mechanism ; we ransack the rocks for 

 the remains of those animals which lived ages ago upon the 

 earth ; we watch how the chick is formed within the egg, 

 and yet we are not satisfied. We seem to hear snatches of 

 music which -we cannot combine. We seek some unifying 

 idea, some conception of the manner in which the world of 

 life has become what it is. 



I. The Idea of Evolution. — We do not dream now, 

 as men dreamed once, that all has been as it is since all 

 emerged from the mist of an unthinkable beginning ; nor 

 can we believe now, as men believed once, that all came 

 into its present state of being by a flash of almighty volition. 

 We still dream, indeed, of an unthinkable beginning, but 

 we know that the past has been full of change ; we still 



T 



