58 



THE STUDY OF ANIMAL LIFE CHAP. 



incipient expression in other species which live in condi- 

 tions where there is no special need of inconspicuousness. 

 Another point is this, that all sorts of shapes and colora- 

 tions occur among animals, and that about some of 

 them all that we can say is " organic idiosyncrasy " ! 

 But it is the nature of the creature to seek environmental 

 gloves to fit its particular tentative fingers, and this 



FIG. 12. LEAF-INSECT SEATED ON A BRANCH. 

 (From Belt.) 



leads to the idea that some of the " invisible animals ' 

 may seek out the surroundings that suit them. Some 

 clever creatures, such as spiders, may learn to hide 

 among the lichens and on the bark which they most 

 resemble. In certain cases it has been proved experi- 

 mentally that this is done, not so much with full aware- 

 ness, as in obedience to certain subtle physiological 

 promptings. 



In a few cases, doubtless to be added to, the value of 



