THE DOGMA OF EVOLUTION 



generations of animals and plants. The form any va- 

 riation will take is a mystery revealed at birth, and, as 

 that is exactly the meaning of "innate," why should 

 we not frankly use the word until the biologists can 

 formulate laws which will predict the characteristics 

 of offspring before births 



Having postulated the general law of variability 

 as the fundamental difference between organic and 

 inorganic bodies, Darwinism next tries to explain 

 how certain variations in a species become fixed by 

 progressive increase to produce new species, which 

 differ morphologically, with pronounced differences 

 in structure, and physiologically, or functionally, so 

 that individuals of the old and new species are mu- 

 tually sterile. 



A cause for the creation of a new species was first 

 proposed by Buff on who believed that an organism 

 changed in order to adapt itself to meet changed con- 

 ditions of its environment, principally those of tem- 

 perature, moisture, and food. Thus an animal covers 

 itself with thicker fur to protect itself against the 

 chill of winter, and others have a winter pelt of white 

 fur as a further protection since that colour is the best 

 reflector of heat. The heat of the animal's body is thus 

 more completely reflected back to its body and does 

 not radiate to the colder air, just as a tea-pot is pol- 

 ished and white to maintain its contents hot. Such 

 correspondences between the environment and the or- 



C 210 2 



