The Problem of Adaptation 7 



color between the organism and its surroundings, and in 

 neglecting all others, is, as has been already said, a point to 

 be further examined. 



Not only among mammals and birds have many cases of 

 protective coloration been described by writers dealing with 

 this subject, but in nearly every group of the animal kingdom 

 similar cases have been recognized. The green and brown 

 color of lizards may protect them, the green color of many 

 frogs is supposed to conceal them as they sit amongst the 

 plants on the edge of a stream or pond. The gray-brown 

 color of the toad has been described as a resemblance to the 

 dry ground, while the brilliant green of several tree-frogs 

 conceals them very effectively amongst the leaves. Many 

 fishes are brilliantly colored, and it has even been suggested 

 that those living amongst corals and sea-anemonies have 

 acquired their colors as a protection, but Darwin states that 

 they appeared to him very conspicuous even in their highly 

 colored environment. 



Amongst insects innumerable cases of adaptive coloration 

 have been described. In fact this is the favorite group 

 for illustrating the marvels of protective coloration. A few 

 examples will here serve our purpose. The oft-cited case 

 of the butterfly Kallima is, apparently, a striking instance of 

 protective resemblance. When at rest the wings are held 

 together over the back, as in nearly all butterflies, so that 

 only the under surface is exposed. This surface has an 

 unquestionably close resemblance to a brown leaf. It is said 

 on no less authority than that of Wallace that when this 

 butterfly alights on a bush it is almost impossible to dis- 

 tinguish between it and a dead leaf. The special point in 

 the resemblance to which attention is most often called is the 

 distinct line running obliquely across the wings which looks 

 like the midrib of a leaf. Whether the need of such a close 

 resemblance to a leaf is requisite for the life of this butterfly, 

 we do not know, of course, and so long as we do not have 



