90 NATURE SKETCHES IN TEMPERATE AMERICA 



Notwithstanding this, the color of these leaves as compared 

 with the colors and form of the moth's wings, matched very 

 closely, and, generally speaking, formed a most deceptive 

 simulation. The oblique lines across the wings ran in the 

 same direction as those of the rolled leaves on the ground and 

 were highly suggestive of veins. When ^he moths are on the 

 ground, perhaps the protective coloring and form of the moth 

 are most deceptive. Yet it was remarkable how easily the 

 moth, while it was on a green leaf, was taken for a dried leaf 

 which had simply been arrested in its fall to the ground. 



Perhaps one of the most notable features of protection 

 afforded these moths is the disposition of the chestnut coloring 

 on the forward part of the thorax. This arrangement of color 

 has the effect of an abrupt shadow at the front end of the body, 

 corresponding to the hollow and shadow at the stem end of 

 the leaf. The distal ends of the wings often have a scalloped 

 margin, simulating the opposite wavy or toothed margin of 

 the leaf. It is obvious that this arrangement of the color 

 and form of these insects is especially useful against the beech 

 forest bed. The instability of form and color exhibited in 

 these Datana moths is probably due to the varying effect of 

 temperature, light, and moisture, coupled with a changeable 

 environment, and the crossing of the color forms. 



Where intricate adaptations appear in the adult, such 

 as I have just illustrated, it not infrequently happens that the 

 early stages, or instars, in their life history are afforded similar 

 mechanisms of protection. 



I was much surprised one day later in August to find a leafless 

 stem of a bush along the wayside adorned at the top by what 

 looked like, at first glance, some floral display. My error was 

 soon discovered when the branch was pulled down for closer 

 inspection. This pseudo-floral form was shown to consist of 

 numerous Datana caterpillars grouped together in a bunch, 

 in such a way as to produce the illusion of a flower. Each little 

 yellow striped caterpillar had selected its place, acting its part 

 instinctively. Both ends of the body of each larva were curved 

 outwards, and all seemed as rigid and motionless as the petals 

 of a flower. (See plate photographic illustration.) 



These little gregarious caterpillars still immature, were 



