562 Mr. A. H. Thayer on 
Apparently Nature has two main _protective-colour 
schemes; one of which is closely imitative of the very near 
environment 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 species 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 bolder, 
more positive way by furnishing them an upperside 
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 
effacively graded. Would it not be absurd for Nature to 
spend energy in effacing the body while making the wings 
conspicuous? 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 within the 
patches of shadow-colour; as in the genus Caligo es- 
pecially. I mean that Caligo 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 Preces, and Anosia plexippus, for instance, have 
these delicate perspectives 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. plexippus type represent half a 
concave flower. Watch any butterfly of this class, or any 
