COLOR AND rATTKRX IX ANIMALS 



401 



Fin. 248. — Katydid, Ci/rtopfij/llis crcpitnua, from tin* We.-f 

 Indies, with green body and wings resembling tlie Icuve» 

 among which it Uves. (After Sharp.) 



The green katydid singing in the tree-top or sliruhhery is 

 readily known to be there by its musie, })iit jnst wliicli bit of 

 green that we see is katydid, and which is Uuif, is a matter to 

 be decided only by unusually discriminating eyes. The clacking' 

 locust; beating its 

 black wings in the 

 air, is conspicuous 

 enough; but after 

 it has alighted on 

 the ground it is 

 invisible, or, 

 rather, visible but 

 indistinguishable : 

 its gray and brown 

 mottled color pat- 

 tern is simply continuous with that of the soil. The green 

 larvse of the Pierid butterflies lying longitudinally along green 

 grasses simply merge into the color sclieme of their environ- 

 ment. The gray moths rest unpereeived on the bark of the 



tree trunk. Hosts of insect kiiuls 

 do really harmonize with the color 

 pattern of their usual environ- 

 ment, and l)y this correspondence 

 in shade and marking, are dilficult 

 to perceive for wliat they are. 

 Now if the eyes that survey the 

 green foliage or run over the gray 

 bark are those of a jireying bird, 

 lizard, or other enemy, it is (piitc 

 certain — our reason tells us .so in- 

 sistentlv — that this i^ossession bv 

 the insect of color and ])attein 

 tending to make it indistinguisli- 

 able from its innnediate environ- 

 ment is advantageous to it — ad- 

 vantageous to the degree often of 

 savins: its life. Now such a u.^^e 



'^'^^ :a>'-.'- 







Fig. 249.— Small locust of the Colo- 

 rado-Mohave desert on the sand. 



of color and pattern is obviously one which can be witlesprea<l 

 through the insect class, and may be, to many sju'cies wliicli 

 lead lives exposed to the attacks of in.sectivorous animals, of 

 large — even of life and death — importance. And naturalists, 



