General Protective Resemblance.— Cases in illustration are the white animals of the Arctic regions, where extreme cold and dryness have turned the hair of the polar bear and the feathers of the snowy owl white. This applie-s to species; the individual ptarmigan, ermine, hare, fox, etc., turn white in winter, but of a russet hue in summer, due to the differing light reflected from -the ground in summer and the snow in winter. The ptarmigan, grouse, prairie chicken and the like, which build open nests, are protectively colored, while the conspicuously marked kingfisher, parrot, etc., build a nest which conceals the sitting bird.
The under side of the wings of certain but terflies, such as the species of Polygonia, Su vanessa antiopa and the East Indian Va!lima, are assimilated in color, together with their often ragged outlines, to dead and tattered leaves; when the butterfly is resting on the ground or in bushes among the dead leaves, it is difficult to distinguish. On the other hand the upper side of the wings are conspicuously marked with reddish hues and conspicuous bars. In the light of the Thayer theory these mark ings, although conspicuous, became meaning less bits of color in harmony with the environ ment, and thus afford practical concealment. Certain moths, when resting on the lichen covered bark of trees, are wonderfully similar to the surroundings, and are thus protected from the attacks of birds or lizards. In the Arctic regions and in Labrador certain butter flies and moths are of the color of lichen covered rocks, so much so that when at rest they are difficult to detect.
Special Protective The most strilcing examples are the measuring worms, or geometrid caterpillars, which, when holding themselves out straight and stiff, re semble twigs, not only in shape, but in color and markings; and still more wonderful are those species whose bodies are provided with tubercles which in shape resemble the leaf-bud and other excrescences in the back of the twigs. How to account for the origin of such pro tuberances is a puzzle. The stick-insect is an other example; though not common with us. and supposed to be well protected from the bills of birds, yet in the East Indian Archipelago they are said to be the principal food of one kind of bird. Another example is the famous leaf-insect (phyllium) of Java, in which the wings are very broad, thin and marked with veins like the mid-rib and side-ribs of a leaf. Such instances as these are cited as buttresses to the Thayer theory of concealment.
Recognition Waller and others the stripes of the African antelopes, the up turned white tail of the rabbit and hare, and the bars and other conspicuous marlcings of birds that fly in flocks, are regarded by some as recognition marks, but others consider that this is rather fanciful and that they are pro tective alone.
Warning Certain animals, of which the skunk affords an example, are so marked as to be easily distinguished by their enemies, which, knowing by experience their offensive nature, pass them by. Hence the con
spicuous stripes of the different species of these animals in the New World. There are many cases of brightly colored caterpillars which are avoided by birds and lizards which greedily devour green ones. The conspicuous red, blue and purple spots and stripes are ad vertisement of their inedibility. In Nicaragua, Belt observed that while ducks and fowl fed on ordinary green frogs, a small species gorgeously colored with red and blue was avoided. On offering one to ducks and fowl they all refused to eat it, except one young duck, which took the frog in its mouth, only to drop it, going about jerking its head as if the taste of the frog was nauseous. Although these striking markings are supposed to be the result of natural selection, Eisig's theory that the abundant secretion of pigrnent is the cause of the distastefulness seems better grounded. Indeed a large number of cases of protective mimicry seem due to the direct action of light and warmth in bringing about the varied hues of the pigment —moreover the range of pri mary colors is not very great, and the hues are apparently due to the action of the environ ment, so that we need not, in most cases at least, invoke the somewhat fanciful hypothesis of Wallace, Poulton and others to account for these resemblances. As Eisig claims, the abun &int secretion of pig-rnent has caused the in sects to be inedible, rather than that the bad taste has caused the production of bright colors as an advertisement or warning signal.
Insects Attracted Rather by the Odors of Flowers than Their Colors.— It has been argued by Lubbock and others that the colors of flowers attract insects, and that the gay lines and stripes leading down to the bottom of deep corollas are guides to the nectar. At present this view has been stoutly opposed by Plateau, after many observations, who thinks that the color of flowers has no connection with the visits of insects, but that they are attracted by the odor of the nectar. He finds that any flower is freely visited if it be nectariferous, no matter how colorless or inconspicuous it may be. Many gay flowers are wholly avoided by insects, but on placing nectar at the base of such flowers insects were at once attracted. .It appears from Plateau's observations that color is not a primary factor in attracting in sects to flowers. Though bright blossoms are undoubtedly seen by insects from a distance, when they once reach the flowers it is a matter of indifference to them what their color is — blue, red, yellow, green or white—if they differ from one another in no other respect. Consult Beddard, F. E., (Animal Coloration' (New York 1895); Newbigin, M. I., (Color in Nature) (London 1898) ; Poulton, E. B., (The Colors of Animals) (New York 1890); Thayer, G. H., (Concealing Coloration in the Animal Kingdom) (New York 1909) ; Wallace, A. R., (Natural Selection and Tropical Nature) (New York 1895) • also works by Lubbock, Plateau, Coste, Ure'ch, Eimer, Hoplcins, Weismann, Tenneck.