back is more like that of the rocker reversed; it touches head and tail, and has far less freedom of movement than has the nuthatch. The head of the latter often points straight out from the tree, and the eye takes in all the surroundings to an extent that the creeper's cannot.

Of course it is not safe to claim that one can always put his finger upon the exact thing that makes one species of birds more numerous than an allied species; the conditions of all animal life are complex, and involve many factors more or less obscure. In the present case I am only trying to point out how slight a part color seems to play in the problem, and how prominent a part food plays. Our ruffed grouse holds its own against the gunners, the trappers, the hard winters, and all its numerous natural enemies, not, I think, because it is protectively colored, but because it, too, is a miscellaneous feeder, ranging from berries and insects to buds and leaves. The quail has the same adaptive coloring, but not the same range of food supply, and hence is more easily cut off. Birds that subsist upon a great variety of foods, no matter what their coloring, apparently have the best chance of surviving.

VI

There seem to be two instincts in animal life that work against the influence of environment upon the colors of animals, or the tendency in Nature to

make her neutral grays and browns everywhere

prevail the male instinct of reproduction, which

is major, and the social or gregarious instinct, which is minor, but which, I am inclined to believe, has its effect.

The gregarious birds and mammals are as a rule less locally colored than those of solitary habits. Thus the more gregarious elk and antelope and sheep are less adaptively colored than the more solitary deer. The buffalo had not the usual color of a plains animal; the individual was lost in the mass, and the mass darkened the earth. The musk ox goes in herds and does not put on a white coat in the sub-Arctic regions.

Does a solitary life tend to beget neutral and obscure tints in a bird or beast? The flocking birds nearly all tend to bright colors, at least brighter than their solitary congeners. The passenger pigeon furnished a good example near at hand. Contrast its bright hues with those of the more recluse turtledove. Most of our blackbirds have a strong flocking instinct, and they are conspicuously colored. The sociability of the cedar-birds may help to account for their crests, their banded tails, and their pure, fine browns. As soon as any of the ground birds show a development of the flocking instinct, their hues become more noticeable, as is the case with the junco, the snow bunting, the shore lark, and the lark bunting of the West. Among the tree Fringil

lido the same tendency may be noticed, the flocking crossbills, pine grosbeaks, redpolls, and the like, all being brighter of color than the solitary sparrows. The robin is the most social of our thrushes, and is the brightest-colored.

In the tropics the parrots and parrakeets and macaws are all strikingly colored, and are all very social. Why should not this be so? Numbers beget warmth and enthusiasm. A multitude is gay of spirit. It is always more noisy and hilarious, more festive and playful, than are single individuals. Each member is less a part of its surroundings and more a part of the flock or the herd. Its associations with nature are less intimate than with its own kind. Sociability, in the human species, tends to express itself in outward symbols and decorations, and why may not the brighter colors of the social birds be the outward expression of the same spirit?

The social flamingo does not, in the matter of color, seem to have been influenced by its environment at all. The gregarious instinct is evidently very strong in the species. Mr. Frank M. Chapman found them in the Bahamas living and breeding in great colonies; he discovered what he calls a flamingo city. The birds all moved and acted in concert. Their numbers showed in the distance like an army of redcoats; they made the land pink. They were adapted to their marsh life by their long legs, and to the food they ate by their bills, but their

colors contrasted strongly with their surroundings. The community spirit carried things with a high hand. The same is in a measure true of the ibis, the stork, the crane all birds more or less gregarious, and all birds of more or less gay plumes. But our solitary great blue heron, lone watcher in marshes and by pond and river margins, is obscurely colored, as is the equally solitary little green heron.

Our blue heron will stand for hours at a time on the margin of some lake or pond, or on the top of some forest tree near the water, and the eye might easily mistake him for some inanimate object. He has watched among roots and snags and dead treetops so long that he has naturally come to look like these things. What his enemies are, that he should need to hide from them, other than the fool with the gun, I do not know.

Among gregarious mammals the same spirit seems at work to check or modify the influence of the environment.

The common crow illustrates this spirit in a wider field. The crow is a citizen of the world; he is at home everywhere, but in the matter of color he is at home nowhere. His jet black gives him away at all times and in all places. His great cunning and suspicion - whence do they come? From his experiences with man?

! I do not know that there is very much in this

idea as to the effect of the social instinct upon the colors of animals. I only throw it out as a suggestion.

When we come to the reproductive principle or instinct, then do we strike a dominating influence; then is there contrast and excess and riot; then are there positive colors and showy ornaments; then are there bright flowers, red, orange, white, blue; then are there gaudy plumes of birds, and obtrusive forms and appendages in mammals. The old modesty and moderation of nature are abandoned. It is not now a question of harmony and quietude, but of continuing the species. Masses of color appear in the landscape; silent animals become noisy; birds burst into song, or strut and dance and pose before one another; the marshes are vocal; hawks scream and soar; a kind of madness seizes all forms of life; the quail whistles; the grouse drums in the woods, or booms upon the prairie; the shellfish in the sea, and the dull turtle upon the land, feel the new impulse that thrills through nature. The carnival of the propagating instinct is at hand. For this, and begotten by this, are the gaudy colors and the beautiful and the grotesque ornaments.

As a rule, the females are not implicated in this movement or craze to the extent that the males are. Even among the flowering plants and trees in which the two sexes are separated, the male is showy while the female is inconspicuous. The pollen-yield