PROBLEM OF CAVE BLINDNESS = 253 
blind variant will go on proving all things, and it 
will hold fast to its cave if it gets there. In its 
automatic elimination of the relatively unfit the 
environment does in a metaphorical sense select 
organisms, but the correlated fact is that organisms 
seem often quite literally to select their environ- 
ment. Just as an animal with well-developed eyes 
will try to get out of the cave into which it has been 
washed, so a blind animal arising as a variant in 
the open may actively grope its way in. 
