6 THE FITNESS OF THE ENVIRONMENT 



For them, in fact, the environment, in its 

 past, present, and future, has been an inde- 

 pendent variable, and it has not entered into 

 any of the modern speculations to consider 

 if by chance the material universe also may 

 be subjected to laws which are in the largest 

 sense important in organic evolution. Yet 

 fitness there must be, in environment as well 

 as in the organism. How, for example, could 

 man adapt his civilization to water power if 

 no water power existed within his reach ? 



adjustment to each other of the magnitudes and laws thus 

 selected, the constitution of the world is what we find it, and 

 is fitted for the support of vegetables and animals in a manner 

 in which it could not have been, if the properties and quan- 

 tities of the elements had been different from what they are. 

 We shall here recapitulate the principal of the laws and 

 magnitudes to which this conclusion has been shown to 



apply. 



1. The Length of the Year, which depends on the force of 

 the attraction of the sun, and its distance from the earth. 



2. The Length of the Day. 



3. The Mass of the Earth, which depends on its magni- 

 tude and density. 



4. The Magnitude of the Ocean. 



5. The Magnitude of the Atmosphere. 



6. The Law and Rate of the Conducting Power of the 

 Earth. 



7. The Law and Rate of the Radiating Power of the 



Earth. 



8. The Law and Rate of the Expansion of Water by Heat. 



9. The Law and Rate of the Expansion of Water by Cold, 

 below 40 degrees. 



