White, crimson, emerald green, shining golden yellow, are amongst the colours seen in the eyes of birds. In owls, herons, cormorants, and many other tribes, the brightly-tinted eye is incomparably the finest feature and chief glory. It fixes the attention at once, appearing like a splendid gem, for which the airy bird-body, with its graceful curves and soft tints, forms an appropriate setting. When the eye closes in death, the bird, except to the naturalist, becomes a mere bundle of dead feathers; crystal globes may be put into the empty sockets, and a bold life-imitating attitude given to the stuffed specimen; but the vitreous orbs shoot forth no life-like flames, the “passion and the fire whose fountains are within” have vanished, and the best work of the taxidermist, who has given a life to his bastard art, produces in the mind only sensations of irritation and disgust. In museums, where limited space stands in the way of any abortive attempts at copying nature too closely, the stuffer’s work is endurable because useful; but in a drawing-room, who does not close his eyes or turn aside to avoid seeing a case of stuffed birds — those unlovely mementoes of death in their gay plumes? Who does not shudder, albeit not with fear, to see the wild cat, filled with straw, yawning horribly, and trying to frighten the spectator with its crockery glare? I shall never forget the first sight I had of the late Mr. Gould’s collection of humming-birds (now in the National Museum), shown to me by the naturalist himself, who evidently took considerable pride in the work of his hands. I had just left tropical nature behind me across the Atlantic, and the unexpected meeting with a transcript of it in a dusty room in Bedford Square gave me a distinct shock. Those pellets of dead feathers, which had long ceased to sparkle and shine, stuck with wires — not invisible — over blossoming cloth and tinsel bushes, how melancholy they made me feel!
Considering the bright colour and great splendour of some eyes, particularly in birds, it seems probable that in these cases the organ has a twofold use: first and chiefly, to see; secondly, to intimidate an adversary with those luminous mirrors, in which all the dangerous fury of a creature brought to bay is seen depicted. Throughout nature the dark eye predominates; and there is certainly a great depth of fierceness in the dark eye of a bird of prey; but its effect is less than that produced by the vividly-coloured eye, or even of the white eye of some raptorial species, as, for instance, of the common South American hawk, ‘Asturina pucherani’. Violent emotions are associated in our minds — possibly, also, in the minds of other species — with certain colours. Bright red seems the appropriate hue of anger — the poet Herbert even calls the rose “angrie and brave” on account of its hue — and the red or orange certainly expresses resentment better than the dark eye. Even a very slight spontaneous variation in the colouring of the irides might give an advantage to an individual for natural selection to act on; for we can see in almost any living creature that not only in its perpetual metaphorical struggle for existence is its life safe-guarded in many ways; but when protective resemblances, flight, and instincts of concealment all fail, and it is compelled to engage in a real struggle with a living adversary, it is provided for such occasions with another set of defences. Language and attitudes of defiance come into play; feathers or hairs are erected; beaks snap and strike, or teeth are gnashed, and the mouth foams or spits; the body puffs out; wings are waved or feet stamped on the ground, and many other intimidating gestures of rage are practised. It is not possible to believe that the colouring of the crystal globes, towards which an opponent’s sight is first directed, and which most vividly exhibit the raging emotions within, can have been entirely neglected as a means of defence by the principle of selection in nature. For all these reasons I believe the bright-coloured eye is an improvement on the dark eye.
Man has been very little improved in this direction, the dark eye, except in the north of Europe, having been, until recent times, almost or quite universal. The blue eye does not seem to have any advantage for man in a state of nature, being mild where fierceness of expression is required; it is almost unknown amongst the inferior creatures; and only on the supposition that the appearance of the eye is less important to man’s welfare than it is to that of other species, can we account for its survival in a branch of the human race.
Cerulean eyes; locks comparable in hue to the “yellow hair that floats on the eastern clouds,” and a white body, like snow with a blush on it — what could Nature have been dreaming of when she gave such things to her rudest, most savage humans! That they should have overcome dark-eyed races, and trod on their necks and ruined their works, strikes one as unnatural, and reads like a fable.
Little, however, as the human eye has changed, assuming it to have been dark originally, there is a great deal of spontaneous variation in individuals, light hazel and blue-grey being apparently the most variable. I have found curiously marked and spotted eyes not uncommon; in some instances the spots being so black, round, and large as to produce the appearance of eyes with clusters of pupils on them. I have known one person with large brown spots on light blue-grey eyes whose children all inherited the peculiarity; also another with reddish hazel irides thickly marked with fine characters resembling Greek letters. This person was an Argentine of Spanish blood, and was called by his neighbours ‘ojos escritos’, or written eyes. It struck me as a very curious circumstance that these eyes, both in their ground colour and the form and disposition of the markings traced on them, were precisely like the eyes of a species of grebe common in La Plata. Browning had perhaps observed eyes of this kind in some person he had met, when he makes his magician say to Pietro de Abano:
Mark within my eye its iris mystic-lettered — That’s my name!
But we look in vain amongst men for the splendid crimson, flaming yellow, or startling white orbs which would have made the dark-skinned brave, inspired by violent emotions, a being terrible to see. Nature has neglected man in this respect, and it is to remedy the omission that he stains his face with bright pigments and crowns his head with eagles’ barred plumes.
The quality of shining in the dark, seen in the eyes of many nocturnal and semi-nocturnal species, has always, I believe, a hostile purpose. When found in inoffensive species, as, for instance, in the lemurs, it can only be attributed to mimicry, and this would be a parallel case with butterflies mimicking the brilliant “warning colours” of other species on which birds do not prey. Cats amongst mammals, and owls amongst birds, have been most highly favoured; but to the owls the palm must be given. The feline eyes, as of a puma or wild cat, blazing with wrath, are wonderful to see; sometimes the sight of them affects one like an electric shock; but for intense brilliance and quick changes, the dark orbs kindling with the startling suddenness of a cloud illumined by flashes of lightning, the yellow globes of the owl are unparalleled. Some readers might think my language exaggerated. Descriptions of bright sunsets and of storms with thunder and lightning would, no doubt, sound extravagant to one who had never witnessed these phenomena. Those only who spend years “conversing with wild animals in desert places,” to quote Azara’s words, know that, as with the atmosphere, so with animal life, there are special moments; and that a creature presenting a very sorry appearance dead in a museum, or living in captivity, may, when hard pressed and fighting for life in its own fastness, be sublimed by its fury into a weird and terrible object.
Nature has many surprises for those who wait on her; one of the greatest she ever favoured me with was the sight of a wounded Magellanic eagle-owl I shot in Patagonia. The haunt of this bird was an island in the river, overgrown with giant grasses and tall willows, leafless now, for it was in the middle of winter. Here I sought for and found him waiting on his perch for the sun to set. He eyed me so calmly when I aimed my gun, I scarcely had the heart to pull the trigger. He had reigned there so long, the feudal tyrant of that remote wilderness! Many a water-rat, stealing like a shadow along the margin between the deep stream and the giant rushes, he had snatched away to death; many a spotted wild pigeon had woke on its perch at night with his cruel crooked talons piercing its flesh; and beyond the valley on the bush uplands many a crested tinamou had been slain on her nest and her beautiful glossy dark-green eggs left to grow pale in the sun and wind, the little lives that were in them dead because of their mother’s death. But I wanted that bird badly, and hardened my heart; the “demoniacal laughter” with which he had so often answered the rushing sound of the swift black river at eventide would be heard no more. I fired; he swerved on his perch, remained suspended for a few moments, then slowly fluttered down. Behind the spot where he had fallen was a great mass of tangled dark-green grass, out of which rose the tall, slender boles of the trees; overhead through the fretwork of leafless twigs the sky was flushed with tender roseate tints, for the sun had now gone down and the surface of the earth was in shadow. There, in such a scene, and with the wintry quiet of the desert over it all, I found my victim stung by his wounds to fury and prepared for the last supreme effort. Even in repose he is a big eagle-like bird; now his appearance was quite altered, and in the dim, uncertain light he looked gigantic in size — a monster of strange form and terrible aspect. Each particular feather stood out on end, the tawny barred tail spread out like a fan, the immense tiger-coloured wings wide open and rigid, so that as the bird, that had clutched the grass with his great feathered claws, swayed his body slowly from side to side — just as a snake about to strike sways his head, or as an angry watchful cat moves its tail — first the tip of one, then of the other wing touched the ground. The black horns stood erect, while in the centre of the wheel-shaped head the beak snapped incessantly, producing a sound resembling the clicking of a sewing-machine. This was a suitable setting for the pair of magnificent furious eyes, on which I gazed with a kind of fascination, not unmixed with fear when I remembered the agony of pain suffered on former occasions from sharp, crooked talons driven into me to the bone. The irides were of a bright orange colour, but every time I attempted to approach the bird they kindled into great globes of quivering yellow flame, the black pupils being surrounded by a scintillating crimson light which threw out minute yellow sparks into the air. When I retired from the bird this preternatural fiery aspect would instantly vanish.
The dragon eyes of that Magellanic owl haunt me still, and when I remember them, the bird’s death still weighs on my conscience, albeit by killing it I bestowed on it that dusty immortality which is the portion of stuffed specimens in a museum.
The question as to the cause of this fiery appearance is one hard to answer. We know that the source of the luminosity in owls’ and cats’ eyes is the ‘tapetum lucidum’ — the light-reflecting membrane between the retina and the sclerotic coat of the eyeball; but the mystery remains. When with the bird, I particularly noticed that every time I retired the nictitating membrane would immediately cover the eyes and obscure them for some time, as they will when an owl is confronted with strong sunlight; and this gave me the impression that the fiery flashing appearance was accompanied with, or followed by, a burning or smarting sensation. I will here quote a very suggestive passage from a letter on this subject written to me by a gentleman of great attainments in science: “Eyes certainly do shine in the dark — some eyes, e.g. those of cats and owls; and the scintillation you speak of is probably another form of the phenomenon. It probably depends upon some extra-sensibility of the retina analogous to what exists in the molecular constitution of sulphide of calcium and other phosphorescent substances. The difficulty is in the ‘scintillation’. We know that light of this character has its source in the heat vibrations of molecules at the temperature of incandescence, and the electric light is no exception to the rule. A possible explanation is that supra-sensitive retinae in times of excitement become increasedly phosphorescent, and the same excitement causes a change in the curvature of the lens, so that the light is focussed, and ‘pro tanto’ brightened into sparks. Seeing how little we know of natural forces, it may be that what we call light in such a case is eye speaking to eye — an emanation from the window of one brain into the window of another.”
Probably all those cases one hears and reads about — some historical — of human eyes flashing fire and blazing with wrath, are mere poetic exaggerations. One would not look for these fiery eyes amongst the peaceful children of civilisation, who, when they make war, do so without anger, and kill their enemies by machinery, without even seeing them; but amongst savage or semi-savage men, carnivorous in their diet, fierce in disposition, and extremely violent in their passions. It is precisely amongst people of this description that I have lived a great deal. I have often seen them frenzied with excitement, their faces white as ashes, hair erect, and eyes dropping great tears of rage, but I have never seen anything in them even approaching to that fiery appearance described in the owl.
Nature has done comparatively little for the human eye, not only in denying it the terrifying splendours found in some other species, but also in the minor merit of beauty. When going about the world one cannot help thinking that the various races and tribes of men, differing in the colour of their skins and in the climates and conditions they live in, ought to have differently-coloured eyes. In Brazil, I was greatly struck with the magnificent appearance of many of the negro women I saw there; well-formed, tall, majestic creatures, often appropriately clothed in loose white gowns and white turban-like head-dresses; while on their round polished blue-black arms they wore silver armlets. It seemed to me that pale golden irides, as in the intensely black tyrant-bird ‘Lichenops perspicillata’, would have given a finishing glory to these sable beauties, completing their strange unique loveliness. Again in that exquisite type of female beauty which we see in the white girl with a slight infusion of negro blood, giving the graceful frizzle to the hair, the purple-red hue to the lips, and the delicate dusky terra-cotta tinge to the skin, an eye more suitable than the dark dull brown would have been the intense orange-brown seen in some lemurs’ eyes. For many very dark-skinned tribes nothing more beautiful than the ru............