ADAPTIVE COLORATION' 219 



for hours along the eaten or torn edge of a basswood leaf, in 

 which position it bears an extremely deceptive resemblance to 

 the partially dead border of a leaf. The weevils that drop to 

 the ground and remain immovable are often indistinguishable 



FIG. 242. 



Caterpillar of Schizura ipomace clinging to a torn leaf. Natural size. 



to the collector on account of their likeness to bits of soil or 

 little pebbles. Everyone has noticed the extent to which some 

 of the grasshoppers resemble the soil in color; Trimerotropis 

 maritima is practically invisible against the gray sand of the 

 seashore or other places to which it restricts itself; and Dis- 

 sosteira Carolina, which varies greatly in color, ranging from 

 ashy gray to yellowish or to reddish brown, is commonly found 

 on soil of its own color. 



Adventitious Resemblance. If, instead of hastily ascrib- 

 ing all cases apparently of protective resemblance to the action 

 of natural selection, one inquires into the structural basis of 

 the resemblance in each instance, it is found that some cases 

 can be explained, without the aid of natural selection, as being 



