56 EVOLUTION, SOCIAL. AND ORGANIC 



water and it is as a consequence fertile and 

 "green." In such a country green insects and 

 green reptiles will be selected, because a green 

 background will render them almost invisible 

 to their enemies. Individuals of other colors 

 will make their appearance by variation, but 

 they will be such plain targets to their enemies, 

 they will be devoured before they reach 

 breeding age and have a chance to reproduCjP 

 the variation. 



But suppose desiccation (drying up) sets 

 in. The country loses its water supply, as 

 Krapotkin has shown to have been the case in 

 North West Mongolia and East Turkestan, 

 leading to the enforced exodus of the barbar- 

 ians. Now green will disappear and brown or 

 yellow — say brown — takes its place. While this 

 change will not, so far as we know, cause in- 

 sects and lizards to breed brown instead of 

 green, it will ensure the survival or "selection" 

 of such as are born brown and the destruction 

 of those who breed true to their green ancestors. 

 Now every atavistic return to green will be 

 mercilessly weeded out, just as, when the coun- 

 try was well-watered and green, every sporadic 

 production of brown was done to death. 



This is the biological foundation of that 

 environment philosoph}^ v:hich noAV pervades 

 all our thinking. Change the physical environ- 



