676 ZOOLOGY. 



tree, prepared to spring upon the deer passing underneath, 

 is protected from observation by its brown neutral color, 

 while the bars and lines of the tiger are said to resemble the 

 lights and shades of the jungle grass in which it lies in wait 

 for its prey. The- prairie-dog, the deer, buffalo and ante- 

 lope on the Western plains, are concealed by their resem- 

 blance in color to the soil, or to the bushes on its surface. 



Among insects, the grasshoppers nearly always harmonize 

 in color with the general, hue of the fields in which they 

 abound ; insects on light-colored sandy beaches are often 

 pale, as if bleached out by the sun's rays. Alpine and arctic 

 butterflies and moths, which have limited powers of flight, 

 when nestling on lichen-covered rocks, are difficult to detect. 



Fig. 542. A Katydid-like form resembling a leaf. 



Certain orthopterous insects resemble leaves ; such are 

 certain katydids (Fig. 542), and especially the famous leaf- 

 insect, Phyllium siccifolium Linn. (Fig. 543), which strik- 

 ingly resembles a green leaf. The stick-insects (Fig. 544) 

 also would be easily mistaken for the twigs of trees or stalks 

 of leaves, one species (Fig. 544) representing a moss-grown 

 twig. The under sides of the wings of our native Grapta 

 butterflies have the color of dead leaves, so that when they 

 are at rest they resemble a withered dry leaf. The most 

 perfect resemblance to a leaf with its stem is the Xallima 

 butterfly when setting at rest with its wings folded over its 



