BUTTERFLY SLEEP

Fond as the butterflies are of the light and sun, they dearly love their beds. Like most fashionable people who do nothing, they stay there very late. But their unwillingness to get up in the morning is equalled by their equal desire to leave the world and its pleasures early and be asleep in good time. They are the first of all our creatures to seek repose. An August day has about fifteen hours of light, and for that time the sun shines for twelve hours at least; but the butterflies weary of sun and flowers, colour and light, so early that by six o'clock, even on warm days, many of them have retired for the night. I climbed Sinodun Hill, on a cold, windy afternoon, and found that hundreds of butterflies were all falling asleep at five o'clock. Their dormitory was in the tall, colourless grass, with dead seed-heads, that fringes the tracks over the hills, or the lanes that cross the hollows. Common blues were there in numbers, and small heath butterflies almost as many. The former, each and every one of them, arrange themselves to look like part of the seed-spike that caps the grass-stem. Then the use and purpose of the parti-coloured grey and yellow under-colouring of their wings is seen. The butterfly invariably goes to sleep head downwards, its eyes looking straight down the stem of the grass. It folds and contracts its wings to the utmost, partly, perhaps, to wrap its body from the cold. But the effect is to reduce its size and shape to a narrow ridge, making an acute angle with the grass-stem, hardly distinguishable in shape and colour from the seed-heads on thousands of other stems around.[1] The butterfly also sleeps on the top of the stem, which increases its likeness to the natural finial of the grass. In the morning, when the sunbeams warm them, all these grey-pied sleepers on the grass-tops open their wings, and the colourless bennets are starred with a thousand living flowers of purest azure. Side by side with the "blues" sleep the common "small heaths." They use the grass-stems for beds, but less carefully, and with no such obvious solicitude to compose their limbs in harmony with the lines of the plant. They also sleep with their heads downwards, but the body is allowed to droop sideways from the stem like a leaf. This, with their light colouring, makes them far more conspicuous than the blues. Moreover, as grass has no leaves shaped in any way like the sleeping butterfly, the contrast of shape attracts notice. Can it be that the blues, whose brilliant colouring by day makes them conspicuous to every enemy, have learnt caution, while the brown heaths, less exposed to risk, are less careful of concealment? Be it noticed that moths and butterflies go to sleep in different attitudes. Moths fold their wings back upon their bodies, covering the lower wing, which is usually bright in colour, with the upper wing. They fold their antennas back on the line of their wings. Butterflies raise the wings above their bodies and lay them back to back, putting their antennae between them if they move them at all. On these same dry grasses of the hills, another of the most brilliant insects of this country may often be seen sleeping in swarms - the carmine and green burnet moth. But it is a sluggish creature, which often seems scarcely awake in the day, and its surrender to the dominion of sleep excites less surprise than the deep slumber of the active and vivacious butterflies. The "heaths" and "blues" should perhaps be regarded as the gipsies of the butterfly world, because they sleep in the open. They are even worse off than the nomads, because, like that regiment sleeping in the open which the War Office lately refused to grant field allowance to on the ground that they were "not under canvas," they do not possess even a temporary roof. What we may call the "garden butterflies," especially the red admirals, often do seek a roof, going into barns, sheds, churches, verandahs, and even houses to sleep. There, too, they sometimes wake up in winter from their long hibernating sleep, and remind us of summer days gone by as they flicker on the sun-warmed panes. Mrs. Brightwen established the fact that they sometimes have fixed homes to which they return. Two butterflies, one a brimstone, the other, so far as the writer remembers, a red admiral, regularly came for admission to the house. One was killed by a rain-storm when the window was shut; the other hibernated in the house. Probably it was as a sleeping-place and bedroom that the butterflies made it their home. There is a parallel instance, mentioned by a Dutch naturalist quoted by Mr. Kirby, when a butterfly came night after night to sleep on a particular spot in the roof of a verandah in the Eastern Archipelago. In the East the sun itself is so regular and so rapid in rising and setting that the sleeping hours of insects and birds are far more regular than in temperate lands, with their shifting periods of light and darkness. Our twilight, that season that the tropics know not, has produced a curious race of moths, or rather, a curious habit confined to certain kinds. They are the creatures neither of day nor of night, but of twilight. They awake as twilight begins, go about their business and enjoy a brief and crepuscular activity, and go to sleep as soon as darkness settles on the world. At the first glimmer of the dawn they awaken again to fly till sunrise, when they hurry off like the fairies, and sleep till twilight falls again.