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FOUNDATIONS OF BIOLOGY 



knows innumerable instances. The song of the green Katy- 

 did readily guides one to its immediate vicinity, but it is quite 

 another matter to distinguish its leaf-green wings among the 

 foliage of its retreat. (Fig. 169.) One is attracted by the 



FIG. 170. Catocala lacrymosa; A, wings expanded, exposing the highly 

 colored hind-wings; B, resting on bark. (From Folsom.) 



striking colors of an Underwing Moth (Catocala) while in 

 flight, but is at a loss to find the insect when scarlet or orange 

 is obscured by the overlapping grayish-mottled fore-wings 

 blending with the tree trunk where it has come to rest. (Fig. 



