A GAME OF HIDE AND SEEK. 667 



quite different species, whicli when at rest closely resemble the 

 lichen-covered rocks. This resemblance is very striking, and is found 

 in all stages of the insect's existence. If now you go to a lowland 

 meadow, still another color phase will be found to prevail — the green 

 grass is swarming with the so-called " long-horned " grasshoppers^ 

 which are green throughout, with linear bodies and long, slender legs 

 and antennae. 



Each of these three groups of insects is adapted to its particular 

 habitat. All are constantly persecuted by birds, and have been so 

 persecuted for unnumbered ages in the past. In every generation the 

 individuals have varied, some toward a closer resemblance to environ- 

 ment, others in an opposite direction. The more conspicuous insects 

 have been constantly taken, and the least conspicuous as constantly 

 left to reproduce. Were the three groups to change places to-day, 

 the green grasshoppers from the meadows going to sandy surfaces, 

 the sand-colored locusts going to rocky hills, and the " mossbacks '' 

 from the hills to the lowland meadows, each would become con- 

 spicuous, and the birds would have such a feast as is seldom spread 

 before them. 



The species living on sand and rocks are often " flushed " by 

 birds. Those which flew but a few feet would be likely to be cap- 

 tured by the pursuing bird; those which flew farther would stand a 

 better chance of escaping. Similarly, those which flew slowly and 

 in a straight line would be more likely to be caught than those which 

 flew rapidly and took a zigzag course. As a consequence of the 

 selection thus brought about through the elimination of those which 

 flew slowly along the straight and narrow way that led to death, you 

 will find that most locusts living in exposed situations when startled 

 fly some distance in a rapid, zigzag manner.- 



But still another element of safety has been introduced by some 

 species of these locusts through the adoption of the color tactics 

 of the Catocala moths. The under wings of the common Carolina 

 locust — the species most abundant along the highway — are black, 

 bordered with yellowish white. The base of the hind wings of a 

 related species living on the Western plains is bluish, while in the 

 large coral-winged locust of the Eastern States the hind wings are 

 red, bordered with black. In nearly all of the species of these 

 locusts frequenting open localities where they are liable to disturb- 

 ance by birds or other animals, the hind wings exhibit contrasting 

 colors in flight. Most of them also fly in a zigzag line, and alight in 

 a most erratic manner. Many times I have had difficulty in deter- 

 mining the exact landfall of one of these peculiar creatures, and I 

 believe Lord Walsingham's suggestion is well exemplified in them. 



