Evolution: The Quest of Truth 163 



to conceive of a perfectly stable and stationary 

 creation. If all offspring were to be precisely 

 like their parents, competition would soon be- 

 come inconceivably more intense. 



Direct considerations. 



Objective evidences of organic evolution 

 may be ranged as following: 



The testimony of paleontology, or the 

 torn and broken pages of the book of life 

 preserved to us in the rocks. 



The evidence of embryology. 



The evidence of comparative anatomy and 

 physiology. 



Resemblances of types or genealogies 

 which allow objects to be classified. 



The evidence of successive increase in com- 

 plexity and differentiation, or the growth of 

 " the tree of life." 



The great fact of adaptation to environment. 



The vagaries of distribution, which are 

 best explained by the evolution hypothesis. 



The fact of variation, and the frequency 

 of intergradient forms. 



