Color and Pattern and their Uses 
585 
lying longitudinally along green grasses simply merge into the color scheme 
of their environment. The gray moth rests unperceived on the bark of 
the tree-trunk. Hosts of insect kinds do really thoroughly harmonize with 
the color-pattern of their usual environment, and by this correspondence 
in shade and marking are difficult to perceive for what they are. Now 
if the eyes that survey the green foliage or run over the gray bark are those 
of a preying bird, lizard, or other enemy of the insect, it is quite certain— 
our reason tells us so insistently—that this possession by the insect of color 
and pattern tending to make it indistinguishable from its immediate environ¬ 
ment is advantageous to it: advantageous to the degree of often saving its 
life. Now such a use of color and pattern is obviously one which can be 
wide-spread through the insect class, and may be to many species which 
lead lives exposed to the attacks of insectivorous animals of large—even 
of life and death—importance. And naturalists, most of them at least, 
believe that this kind of usefulness is real, and that it is the principal clue 
to the chief significance of color and pattern. And this not alone in the 
case of insects, but of most other animals as well. 
From this point of view, namely, that color-patterns may be of advantage 
in the struggle for existence, just as strength, swiftness, and other capacities 
and conditions are, the specialization and refinement, all the wide modifica¬ 
tion and variety of colors and patterns, are explicable by the hypothesis of 
their gradual development in time through the natural selection of naturally 
occurring advantageous variations. On this basis, such special instances 
of resemblance to particular parts of the environment, as that shown by 
Kallima in its likeness to a dead leaf, and Diapheromera in its simulation 
of a dry, leafless twig, are simply the logical extremes of such a line of speciali¬ 
zation. 
But the nature observer may be inclined to ask how such brilliant and 
bizarre color-patterns as those of the swallowtail-butterflies and the tiger- 
banded caterpillars of Anosia can be included in any category of “protective 
resemblance” patterns. They are not so included, but are explained inge¬ 
niously by an added hypothesis called that of “warning colors,” while for 
the striking similarities of pattern often noted between two unrelated con¬ 
spicuously colored species still another clever hypothesis is proposed. In 
these cases it is not concealment that the color-pattern effects, but indeed 
just the opposite. Since the pioneer studies of Bates and Wallace and Belt, 
naturalists have been observing and experimenting and pondering these 
exposing as well as these concealing conditions of color and pattern, and 
they have proposed several theories or hypotheses explanatory of the various 
conditions. These hypotheses are plausible; but they are much more than 
that; they are each more or less well backed up by observation and experi¬ 
ment, and some of them have gained a large acceptance among naturalists. 
