I

Not long since. one of our younger naturalists sent me a photograph of a fawn in a field of daisies, and said that he took the picture to show what he considered the protective value of the spots. The white spots of the fawn did blend in with the daisies, and certainly rendered the fawn less conspicuous than it would have been without them, but I am slow to believe that the fawn has spots that it may the better hide in a daisy field, or, in fact, anywhere else, or that the spots have ever been sufficiently protective to have materially aided in the perpetuity of the deer species. What use they have, if any, I do not know, any more than I know what use the spots on the leopard or the giraffe have, or the stripes on the zebra. I can only conjecture concerning their use. The panther does not have spots, and yet it seems to get along just as well without them. The young of the moose and the caribou are not spotted, and yet their habitat is much the same as that of the deer.

Why some forest animals are uniformly dark colored, while others are more or less brilliantly striped or spotted, is a question not easily answered. It is claimed that spotted and striped species are more diurnal in their habits, and frequent bushes and open glades, while the dusky species are more nocturnal, and frequent dense thickets. In a general way this is probably true. A dappled coat is certainly more in keeping with the day than with the night, and with bushes and jungles than with plains or dense forests. But VOL. 95- NO. 6

whether its protective value, or the protective value of the dusky coat, is the reason for its being, is another question.

This theory of the protective coloration of animals has been one of the generally accepted ideas in all works upon natural history since Darwin's time. It regards the color of an animal as much the result of natural selection as any part of its structure, - natural selection picking out and preserving those tints that were the most useful to the animal in concealing it from its enemies or from its prey. If in this world no animal had ever preyed upon another, it is thought that their colors might have been very different, probably much more bizarre and inharmonious than they are at present.

Now I am not going to run amuck upon this generally accepted theory of modern naturalists, but I do feel disposed to shake it up a little, and see, if I can, what measure of truth there is in it. That there is a measure of truth in it I am convinced, but that it has been greatly overworked in our time, and that more has been put upon it than it can bear, of this also I am convinced.

I think we are safe in saying that a bird is protectively colored when the color, as it were, strikes in, and the bird itself acts upon the theory that it is in a measure hidden behind its assimilative plumage. This is true of nearly all the grouse tribe. These birds seem instinctively to know the value of their imitative tints, and are tame or wild according as their tints do or do not match the snow on the ground. Moreover the grouse are all toothsome; and this fact of the toothsomeness of

some birds and the toughness and unsavoriness of others, like the woodpecker, the crow tribe, gulls, divers, cormorants, and the like, has undoubtedly played some part in their natural history. But whether they are dull colored because they are toothsome, or toothsome because they are dull colored - who shall say? Which was first, the sweetness or the color? The flesh of the quail and the partridge having become very delectable and much sought after by many wild creatures, did nature make compensation by giving them their assimilative plumage? or were the two facts inseparable from the first?

The sweetness of an animal's flesh is doubtless determined by its food. I believe no one eats the western road-runner, though it is duller of color than the turkey. Its food is mice, snakes, lizards, centipedes, and other vermin.

Thus far I can follow the protective colorists, but not much farther.

Wallace goes to the extent of believing that even nuts are protectively colored because they are not to be eaten. But without the agency of birds and the small rodents, the wingless nuts, such as chestnuts, acorns, hickory nuts, and butternuts, could never get widely scattered, so that if they were effectively concealed by their colors this fact would tend to their extinction.

If the colors of animals were as vital a matter, and the result of the same adaptive and selective process, as their varied structures, which Darwin and Wallace teach, then it would seem to follow that those of the same habits and of the same or similar habitat would be similar or identical in color, which is not commonly the case. Thus the waders among the birds all have long legs and long necks, but they are not all of the same color. The divers all have short legs placed far in the rear, but they vary greatly in color markings. How greatly the ducks differ in coloration, though essentially the same in structure! Our tree warblers are of all hues and combinations of hues, though so alike in habit and form. The painted

bunting in the southwest is gaudily colored, while its congeners are all more plainly dressed.

In England the thrush that answers to our robin, being almost identical in form, manner, and habit, is black as a coal. The crow tribe are all built upon the same plan, and yet they show a very great diversity of colors. Why is our jay so showily colored, and the Canada jay so subdued in tint?

The humming birds do not differ much in their anatomy, but their tints differ as much as do those of precious stones. The woodpeckers show a variety of markings that cannot be accounted for upon any principle of utility or of natural selection. Indeed, it would seem as if in the colors of birds and mammals nature gave herself a comparatively free hand, not being bound by the same rigid necessity as in their structures. Within certain limits something like caprice or accident seems to prevail. The great law of assimilation, or harmonious blending, of which I shall presently have more to say, goes on, but it is checked and thwarted and made sport of by other tendencies.

Then the principle of coloration of the same species does not always hold good in different parts of the earth. Thus our grouse and other gallinaceous birds are obscurely marked, like the ground they live upon, but in the Orient, in India and China, the allied species are brightly colored, and we have the golden pheasant, and the Argus pheasant, and others.

In our hemisphere the swans are white, the pigeons are blue, and the parrots are green. In Australia the swans are black, and there is a black pigeon and a black parrot. In the desert of Sahara most of the birds are desert-colored, but there are some that are blue, and others that are black or brown and white. It is said that the Arctic fox which is snow-white in most other places remains blue all winter in Iceland. No doubt there are reasons for all these variations, but whatever these reasons are, they do not seem to favor the theory of protective coloration.

Mr. Wallace in one of his essays points out the effect of locality on color, many species of unrelated genera both among insects and among birds being marked similarly, with white or yellow or black like the effect of some fashion that has spread among them. In the Philippine Islands metallic hues are the fashion; in some other islands very light tints are in vogue; in other localities unrelated species favor crimson or blue. Mr. Wallace says that among the different butterflies of different countries this preference for certain colors is as marked as it would be if the hares, marmots, and squirrels of Europe were all red with black feet, while the corresponding species of Central Asia were all yellow with black heads, or as it would be if our smaller mammals, the coon, the possum, the squirrels, all copied the black and white of the skunk. The reason for all this is not apparent, though Wallace thinks that some quality of the soil which effects the food may be the cause. It is like the caprice of fashion. In fact, the exaggerated plumes and bizarre colors and monstrous beaks of many birds in both hemispheres have as little apparent utility, and seem quite as much the result of caprice, as are any of the extreme fashions in dress among human beings.

Most of our black birds flock in the fall, and they are not protectively colored, but the bobolinks, which also flock then, do then assume neutral tints. Why the change in the one case and not in the other, since both species feed in the brown marshes? Most of our own ground birds are more or less ground colored, but here is the chewink on the ground, amid the bushes, with the brown oven bird and the brown thrasher, with conspicuous markings of white and black and red. Here are some of the soft gray and brown tinted warblers nesting on the ground, and here is the more conspicuous striped black and white creeping warbler nesting by their side. Behold the rather dull colored great crested flycatcher concealing its nest in a hollow limb, and its congener, the

brighter feathered king bird, building its nest openly on the branch above.

Hence, whatever truth there may be in this theory of protective coloration, one has only to look about him to discover that it is a matter which nature does not have very much at heart, She plays fast and loose with it on every hand. Now she seems to set great store by it, the next moment she discards it entirely.

If dull colors are protective, then bright colors are non-protective or dangerous, and one wonders why all birds of gay feather have not been cut off and the species exterminated: or why, in cases where the males are bright colored and the females of neutral tints, as with our scarlet tanager, and indigo bird, the females are not greatly in excess of the males, which does not seem to be the

case.

II

We arrive at the idea that neutral tints are protective from the point of view of the human eye. Now if all animals that prey upon others were guided by the eye alone there would be much more in the theory than there is. But none of the predaceous four-footed beasts depend entirely upon the eye. The cat tribe does to a certain extent, but these creatures stalk or waylay moving game, and the color does not count. A white hare will evidently fall a prey to a lynx or a cougar in our winter woods as easily as a brown rabbit; and will not a desert-colored animal fall a prey to a lion or a tiger just as readily as it would if it were white or black? Then the most destructive tribes of all, the wolves, the foxes, the minks, the weasels, the skunks, the coons, and the like, depend entirely upon scent. The eye plays a very insignificant part in their hunting, hence again the question of color is eliminated.

Birds of prey depend upon the eye, but they are also protectively colored, and their eyes are so preternaturally sharp that no disguise of assimilative tints is of any avail against them. If both the

hunted and its hunter are concealed by their neutral tints, of what advantage is it to either? If the brown bird is hidden from the brown hawk, and vice versa, then are they on an equal footing in this respect, and the victory is to the sharpest eyed. If the eye of the hawk sharpens as the problem of his existence becomes more difficult, as is doubtless the case, then is the game even, and the quarry has no advantage, the protective color does not protect.

Why should the owl, which hunts by night, be colored like the hawk, that hunts by day? If the owl were red, or blue, or green, or black, or white, would it not stand just as good a chance of obtaining a subsistence? Its silent flight, its keenness of vision, and the general obscurity, are the main matters. At night color is almost neutralized. Would not the lynx and the bobcat fare just as well if they were of the hue of the sable or the mink? Are their neutral grays or browns any advantage to them? The gray fox is more protectively colored than the red; is he therefore more abundant? Far from it; just the reverse is true. The same remark applies to the red and the gray squirrels.

The northern hare, which changes to white in winter, would seem to have an advantage over the little gray rabbit, which is as conspicuous upon the snow as a brown leaf, and yet such does not seem to be the case. It is true that the rabbit often passes the day in holes and beneath rocks, and the hare does not; but it is only at enemies of eachwild cats, owls

night that the natural

foxes, minks, weasels, are abroad.

It is thought by Wallace and others that the skunk is strikingly marked as a danger signal, its contrast of black and white warning all creatures to pass by on the other side. But the magpie is marked in much the same way, as is also our bobolink which, in some localities, is called "the skunk bird," and neither of these birds has any such reason to advertise itself as has the skunk. Then here is the porcupine, with its panoply of spears,

as protectively colored as the coon or the woodchuck, why does not it have warning colors also? The enemy that attacks it fares much worse than in the case of its black and white neighbor.

The ptarmigan is often cited as a good illustration of the value of protective coloration,-white in winter, particolored in spring, and brown in summer, — always in color blending with its environment. But the Arctic fox would not be baffled by its color; it goes by scent; and the great snowy owl would probably see it in the open at any time of year. On islands in Bering Sea we saw the Arctic snow bird, white as a snowflake in midsummer, and visible afar. Our northern grouse carry their gray and brown tints through our winters, and do not appear to suffer unduly from their telltale plumage. If the cold were as severe as it is farther north, doubtless they, too, would don white coats, for the extreme cold, no doubt, plays an important part in this matter, this and the long Arctic nights. Sir John Ross protected a Hudson's Bay lemming from the low temperature by keeping it in his cabin, and the animal retained its summer coat; but when he exposed it to a temperature of thirty degrees below zero, it began to change to white in a single night, and at the end of a week was almost entirely so. It is said that in Siberia domestic cattle and horses become lighter colored during the winter, and Darwin says he has known in England brown ponies to become white in winter.

Only one of our weasels becomes white in winter, the ermine, the others keep their brown coats through the year. Is this adaptive color any advantage to the ermine? and are the other weasels handicapped by their brown tints?

The marten, the sable, and the fisher do not turn white in winter, nor the musk ox, nor the reindeer. The latter animals are gregarious, and the social spirit seems to oppose local color.

The long Arctic nights and the intense cold no doubt have much to do with the white of Arctic animals. "Absence of

light leads to diminution or even total abolition of pigmentation, while its presence leads to an increase in some degree proportionate to the intensity of the light." 1

When the variable northern hare is removed to a milder climate, in the course of a few it ceases to turn white in years winter.

The more local an animal is, the more does it incline to take on the colors of its surroundings, as may be seen in the case of the toads, the frogs, the snakes, and many insects. It seems reasonable that the influence of the environment should be more potent in such cases. The grasshoppers in the fields are of all shades of green and brown and gray, but is it probable that these tints ever hide them from their natural enemies the sharpeyed birds and fowls? A grasshopper gives itself away when it hops, and it always hops.

On the sea coast I noticed that the grasshoppers were gray like the sands. What fed upon them, if anything, I could not find out, but their incessant hopping showed how little they sought concealment. The nocturnal enemies of grasshoppers, such as coons and skunks, are probably not baffled at all by their assimilative colors.

Our wood frog, rana sylvaticus, is found throughout the summer on the dry leaves in the woods, and it is red like them. When it buries itself in the leaf mould in the fall for its winter hibernation, it turns dark like the color of the element in which it is buried. Can this last change be for protection also? No enemy sees it or disturbs it in that position, and yet it is as "protectively" colored as in summer. This is the stamp of the environment again.

The toad is of the color of the ground where he fumbles along in the twilight, or squats by day, and yet, I fancy, his enemy, the snake, finds him out without difficulty. He is of the color of the earth because he is of the earth earthy, and the 1 Vernon on Variation in Animals and Plants.

bullfrog is of the color of his element, but there is the little green frog, and the leopard, and the pickerel frogs, all quite showily marked. So there we are, trying to tabulate nature when she will not be tabulated! Whether it be the phrase protective coloration, or the imprint of the environment, with which we seek to capture her, she will not always be captured. In the tropics there are gaudily colored tree frogs,-blue, yellow, striped,—frogs with red bodies and blue legs, and these showy creatures are never preyed upon, they are uneatable. But the old question comes up again—are the colors to advertise their uneatableness, or are they the necessary outcome, and would they be the same in a world where no living thing was preyed upon by another? The acids or juices that make their flesh unpalatable may be the same that produce the bright colors. To confound the cause with the effect is a common error. I doubt if the high color of some poisonous mushrooms is a warning color, or has any reference to outward conditions. The poison and the color are probably inseparable.

The muskrat's color blends him with his surroundings, and yet his enemies, the mink, the fox, the otter, trail him just the same; his color does not avail. The same may be said of the woodchuck. What color could he be but earth color? and yet the wolf and the fox smell him out just the same. If he were snow-white or jet-black (as he sometimes is) he would be in no greater danger.

I think it highly probable that our bluebird is a descendant of a thrush. The speckled breast of the young birds indicates this, as does a thrush-like note which one may occasionally hear from it. The bird departed from the protective livery of the thrush and came down its long line of descent in a showy coat of blue, and yet got on just as well as its ancestors. Gay plumes were certainly no handicap in this case. Are they in any case? I seriously doubt it. In fact, I am inclined to think that if the birds and