ADJUSTMENT OF ORGANISMS TO ENVIRONMENT 42 5 



However, in very many species, it may be protective toward 

 a group of stronger species (enemies) and aggressive toward 

 a group of weaker ones 



Resemblance is very often a matter of form and attitude, 

 quite as much as of coloration. The moths shown in figure 

 247 are colored much like the burdock stem on which they 

 rest, but their inconspicuousness is obviously greatly 

 improved by the stub-like attitude in which they hold the 

 body against the side of the stem. Inconspicuousness, may 

 be brought about by loss of color. This is seen in the trans- 

 parent larva of Corethra, and in many free swimming 

 organisms which are viewed by enemies against the lighted 

 background of the sky. 



It is impossible to 

 judge resemblance 

 except in its proper 

 setting. An animal 

 that appears con- 

 spicuous enough in 

 the museum (fig. 

 248) may be well 

 concealed in its 

 native haunts. Cer- 

 tainly the leopard 

 frog with its green 

 skin covered with 

 black blotches sur- 

 rounded by yellow 

 rings is conspicuous 

 enough sitting on a 

 white plate in the 

 laboratory, but any 



FIG. 247. Burdock moths (Metzneria lap.Ua) on a One who has Collected 



dead stem: resemblance "in form and attitude as -f^is frog" loiOWS it is 

 ll as in color. 



