CHAPTER XXI
Sights of the forest—A butterfly bridge—Bird-winged butterflies—“What’s in a name?”—Scientific sensibility—Resemblance v. mimicry—A convenient wrong word—Beauty in nature—Nuptial display—Strange counter-theory—Lucus a non lucendo—Reasoning by contraries—True in Topsy-turvydom—Butterfly courtship—Form and colour—A curious suggestion—Powers of defective eyesight.
THOUGH the principle of protective resemblance, as explained in the last chapter, will account for the colours and markings of those butterflies which imitate the Heliconidæ, it does not explain how the Heliconidæ themselves came to be as they are; for in nature every mark and line and shade has a meaning, and has come into existence by virtue of some law or another. Beauty itself, independently of any arrière pensée, as we may call it—remembering those flower-resembling spiders—requires to be explained.
Nor are the Heliconidæ themselves, though gaudily dressed showy butterflies, anything like so beautiful as many others; for instance, as the Morphos, those giants of their kind, who sweep like stars through the tropical forests on wings whose whole broad surface is blue, but a blue that flashes like a drawn sword and has a hundred glints and gleamings of ever-varying light. High-fliers they are for the most part, keeping to the tops of the trees, but every morning, and always at the same time, they make a descent into the glades and alleys of the forest, where for a little they flap lazily backwards and forwards, now in eclipse, now flashing forth into sunlight, as though to flaunt their beauties in the face of the lower world. Such openings in the primeval forest are often made by the fall of great trees—for even where the axe is not there is death in the midst of life—and as these majestic insects sail high above them in a world of air and light, their shadows fall upon the place beneath, and trace their course along the ground. When the sun’s rays strike into them, such clearings become the gathering grounds of various butterflies. Besides the great Morphos, the flashing of whose wings in the sunlight can be seen sometimes a quarter of a mile away,[[112]] various species of Heliconeas—the one we have just been reading about—whose black wings are in some species spotted with scarlet, in others with white or blue, waltz about the bushes or undergrowth, “dancing in the chequered shade”; fritillaries somewhat like our own, but of larger size and more effective colouring, fly higher up, about the tree-trunks, whilst over the ground itself, carpeted as it often is with flowers fallen from the leafy world above, and scenting the air, ghost-like butterflies, whose clear, transparent wings are without any colouring matter, ceaselessly hover and flit.
Wherever there is a river, many-coloured armies, bivouacked amidst its various shoals and reefs, sit sucking water through, the moist particles of the sand, whilst others, in even greater numbers, pass and repass from one bank to another, making, however wide the waterway, an aerial fluttering bridge. Other butterflies, also denizens of the great Brazilian or Central American forests, have broad white wings, shot with a satiny lustre, whilst those of yet another are like glass, with one opaque spot of violet and blue, in the midst of each of them. In flight this spot is the only part that can be seen, and it looks, Bates tells us, “like the wandering petal of a flower.”[[113]] There are swallow-tailed butterflies, too, whose livery of deep, soft green, and deeper velvet black, set off with roseate hues, is amongst the richest of all—“rich, not gaudy,” so at least I should term it, for I have seen it, putting flowers to shame, on the lower slopes of the Himalayas. Here these butterflies—double the size of our Machaon, and of another shape, with racquet-rather than swallow-tails, flew on the open hillside, courting the sun, but in Brazil they keep to the forest depths, where, like Una, they “make a sunshine in the shady place.”
The butterflies of South America are almost rivalled—quite they cannot be—by those of the Malay Archipelago. Here we have the great Bird-winged Butterfly, discovered by Dr. Wallace, who calls it “elegant,” and bestows upon it a name (Ornithoptera Brookeana) which is not quite that.[[114]] However, “What’s in a name? That which we call a Brookeana,” etc.—we must reverse the proposition. There is no describing such a creature—at least, not convincingly. Suffice it to say that its wings “almost resemble those of a sphinx moth in shape,” and are deep, velvety black, but lit up with a band of green feather-like markings, so brilliant and lovely that they reminded its discoverer “of the wing-coverts of the Mexican trogon laid upon velvet”[[114]]—and that for anyone who has seen a trogon, even stuffed and dried, is to say enough. Besides this adornment the great Brookeana has “a broad neck-collar of vivid crimson and a few delicate white touches on the outer margins of the hind wings.”[[114]] Another Ornithoptera without the Brookeana is “the largest, the most perfect, and the most beautiful of butterflies.” The two last, however, are matter of opinion, and I should think myself that a Morpho with its azure wings, sometimes seven inches across, and flashing a quarter of a mile away, would run—or fly—it hard. Then there is a yet more gorgeous species of “Bird-winged Butterfly,” with wings equalling or even exceeding the Morpho’s in expanse, whose ample surface is divided between flame-like orange and a black so deep, rich, and velvety that it seems to glow—“the pride of the Eastern tropics, one of the most gorgeously coloured butterflies in the world.”[[115]]
This was the butterfly that gave Dr. Wallace a headache, “so great was the excitement produced by what will appear to most people a very inadequate cause.”[[115]] Surely not; for the cause here alluded to was not the insect’s beauty—which had been seen before, free and untrammelled, without any such ill-consequence—but its capture and anticipated transference to the cyanide bottle. It was not mere æsthetic emotion, therefore, that produced the headache, but scientific enthusiasm, of which no man need feel ashamed. It is easy for us on such occasions to mistake our feelings, but the clue to them, I think, is this, that however beautiful a creature may be, and however appreciative we may think ourselves of such beauty, yet if we resolve, in the true interests of science, to take that creature’s life, then the scientific spirit must be far stronger in us than mere admiration of its beauty. This test I would apply to another account which Dr. Wallace gives us of the capture of “one of the most magnificent insects that the world contains.” “I trembled,” he says, “with excitement as I saw it coming majestically towards me, and could hardly believe I had really succeeded in my stroke till I had taken it out of the net and was gazing, lost in admiration, at the velvet black and brilliant green of its wings—seven inches across—its golden body, and crimson breast. It is true I had seen similar insects in cabinets at home, but it is quite another thing to capture such oneself—to feel it struggling between one’s fingers, and to gaze upon its fresh and living beauty, a bright gem shining out amid the silent gloom of a dark and tangled forest. The village of Dobbo held that evening at least one contented man.”[[116]] When we consider that the “fresh and living beauty” was caught for the very sake of being made dead and mouldy, and that the “bright gem” which would otherwise have continued to flash in the forest was about to become one of those very same specimens that had been looked at with such an inferior degree of interest, we must admit, I think, that the higher of two passions was predominant here, and that the author, in dwelling only upon the other and lower one—mere delight of the eye—has done himself less than justice.
Mr. Bates, without headaches, has given us some very pleasing pictures of butterfly-life in the tropics, and in doing so he has instinctively, as it were, kept the killing and capturing in the background. “The number and variety of gaily-tinted butterflies,” he tells us, “sporting about in this grove on sunny days, were so great that the bright moving flakes of colour gave quite a character to the physiognomy of the place. It was impossible to walk far without disturbing flocks of them from the damp sand at the edge of the water, where they congregate to imbibe the moisture. They were of almost all colours, sizes, and shapes. I noticed here altogether eighty species belonging to twenty-two different genera. It is a singular fact that, with very few exceptions, all the individuals of these various species thus sporting in sunny places were of the male sex; their partners, which are much more soberly dressed and immensely less numerous than the males, being confined to the shades of the woods. Every afternoon, as the sun was getting low, I used to notice these gaudy, sunshine-loving swains trooping off to the forest, where I suppose they would find their sweethearts and wives.”[[117]] What a delightful scene! Here, “next to the very common sulphur-yellow and orange-coloured kinds, the most abundant were about a dozen species of Eunica, of large size, conspicuous from their liveries of glossy dark blue and purple. A superbly adorned creature, the Callithea Markii, having wings of a thick texture, coloured sapphire blue and orange, was only an occasional visitor. On certain days, when the weather was very calm, two small gilded green species literally swarmed on the sands, their glittering wings lying wide open on the flat surface.”[[117]]