Color and Pattern and their Uses 



603 



these larvae are, they are only occasionally seen, and then usually when "loop- 

 ing" along on the ground or sidewalk. When in their habitual haunts in 

 trees and bushes, the slightest disturbance, as the approach of bird or lizard 

 or human observer, causes them to "go stiff," holding the body (Fig. 789) 



Fig. 789. 



Fig. 790. 



Fig. 789. — .\n inch-worm, larva of geometrid moth, in protective position. (After Jor- 

 dan and Kellogg; natural size.) 

 Fig. 790. — The walking-stick, or twig-insect, Diapheromera jemorala. (Slightly enlarged.) 



rigidly out from the branch or stem to which they cling by the posterior 

 two pairs of prop-legs, and looking so like a short twig, or broken one, that 

 they are only rarely recognized for what they really are. The skin is brown or 



