562 Uv. A. H. Thayer oil 



Apparently Nature has two main protective-colour 

 schemes; one of which is closely imitative of the vcrij near 

 cnviQ'onmcnt of the animal, and applicable to such species 

 as sit close, and keep still, for concealment, as do the tree- 

 toads, moths, goatsuckers, certain snakes, and, among butter- 

 flies, the siDecies of Grapta. (The latter, at least, keep very 

 still when resting, and expose at such times only the rock 

 or bark representation on the under-side of their wings.) 

 Among those butterflies, on the other hand, which have 

 no pronounced habit of protecting themselves in this 

 manner. Nature seems to have been forced to a boldei', 

 more positive way by furnishing them an upper-side 

 bearing a sort of conventionalized representation of the 

 predominant details among which they are destined to 

 move. Flowers, of course, must almost always be present. 

 And always the notes of the conventionalization are perfect. 

 Here is a most impressive argument, viz., so-called con- 

 spicuous butterflies have the body, head and all, exquisitely 

 efifacively graded. Would it not be absurd for Nature to 

 spend energy in effacing the hocly while making the unngs 

 ccmsjncao'us ? The multitude of species, the world over, 

 whose main colour is largely the peculiar fuscous of 

 shadow under vegetation, have in most cases not merely 

 this shadow-colour, which so perfectly coalesces with the 

 shadow and apparently vanishes from the insect, but also 

 a system of exquisitely delicate perspectives witJiin the 

 patches of shadow-colour ; as in the genus Galigo es- 

 pecially. I mean that Galigo is an exquisitely developed 

 representation of the perspectives which an artist sees in 

 peering down through the openings between the flowers. 

 The parts of the world which I know well do not yet 

 furnish me a clear vision why so many butterflies, such as 

 several Frcces, and Anosia plexippms, for instance, have 

 these delicate jDerspectives done in golden brown instead 

 of either shadow-colour or the more delicate flower-colour ; 

 but that this delicate design does represent perspective, 

 and would be wasted if used for any attempt at conspicu- 

 ousness, and that it is entirely akin to the perspectives 

 rendered on perfect shadow-colour in so vast a number of 

 species, is reason enough for' trusting it to prove to be 

 some form of concealment device ; and on red flowers 

 these species show surprisingly little. I myself suspect 

 that butterflies of the A. plcxippits type represent half a 

 concave flower. Watch any butterfly of this class, or any 



