The Struggle for Existence 151 



as he says, that not one is unhappy over the whole earth. But 

 there is another truth, that this world is not a place for the unlit 

 lamp and the ungirt loin, and that when a creature has not armour 

 or weapons or cleverness it must find some path of safety or go 

 back. One of these paths of safety is disguise, and we have illus- 

 trated its evolution. 



