WHEN night finds us in quiet homes, with quiet minds and bodies pleasantly tired, there may come to us the thought of those to whom the evening is as a morning, and whose wakeful and busy time is just beginning.
In many fields of industry work gets fairly under way about the bedtime of the public at large. The newspaper offices are all alight and astir. On the railroads thousands of men are assuming those exacting duties which, for them, turn night into day. The night nurses in hospitals, the sentries in forts, the watch at sea, have all hours of vigilant wakefulness before them.
In the animal world the darkness which lulls one* creature to repose rouses another into in-tensest life. Beasts of prey, which have drowsed through the sunlit hours, wake in the twilight to "seek their meat from God," and migrant birds stretch their wings for a flight which will end only with the dawn.
In the insect world innumerable creatures fly out of countless holes and hiding-places as dusk falls, seeking those flowers of darkness which hold continuous receptions for them through the dewy summer nights.
There is a popular but an erroneous impression that only two or three sorts of blossoms unfold at evening. The night-blooming cereus is so big and splendid that it occupies an undue place in the public mind as the flower of darkness, whose nocturnal habits are shared only by the moon-flower. But if we bethink us that moths draw most of their sustenance from flower-calices, we will realize that there must be a whole category of night-blooming flowers. For though many blossoms do not close at dusk, but keep open house day and night during their whole time of blooming, the buds of most species expand in the sunshine, and the chances are that their sweets will be extracted soon afterward by some diurnal rover.
How, then, does Nature feed the crepiscular moths, which flit abroad at sundown, and the nocturnal moths, which fly in darkness? We realize their numbers, to our cost, if we burn a lamp near an open window on a sultry night. In a museum of natural history we may see them gathered according to their tribes, a mighty host, clad all in night's sombre livery. It would be a formidable undertaking to count the species, and as for the individuals, they must be numberless as the sands of the shore. For them the night-flowers blow, and as the guests are many, the banquet is abundant.
In our gardens and in the fields a number of blossoms expand in the twilight. Some of these close about sunrise, some wilt in the radiance of noon, and some remain open all through the day, and hence are never thought of as nocturnal flowers. But their first freshness and uttermost sweetness are given to the night-moths, and though we may see them blooming in the sunshine, they are really blossoms of the night.
Among garden-flowers the most familiar night-bloomer is the honeysuckle. Its buds open late in the afternoon or in the evening before dusk falls. On a very cloudy day I have seen them expanding as early as half-past three, and in the long June afterglow it may be eight o'clock before the last flowers unfold. They are slender vases filled to the brim with fragrance, which is shed upon the night air, a mute invitation to the vine's best friends, the "hawk" or "sphinx" moths.
Several sorts of these sphinxes visit the flowers during the earlier hours of the night. One, who begins his supper before daylight has faded, is rather larger than a bumble-bee. His body and upper wings are in dull shades of gray and brown, but on his under wings are patches of "sunset"-pink, which show that his habits are crepuscular rather than nocturnal. For the true night-moths, the "butterflies of the earth's shadow," are dun-colored, gray, or white. Nature, which never wastes, has withheld from them the colors which would be invisible to their mates, and has sent them abroad as sombrely clad as so many nuns and friars. This little visitor, with the bright colors on his wings, roves abroad in the evening and morning twilight when there is enough light to reveal his adornment to his lady-love.
Later in the night, when he has supped, the vine will be visited by larger sphinxes, dusky or sad-colored, as are all insects which fly in darkness. All these moths have large proboscises, which can reach down to the bases of deep and slender blossom-tubes, and which coil up like watchsprings when the insects are at rest.
They sip like humming-birds, poised above the flower on whirring wings, and hence are sometimes known as "humming-bird moths." They are called "hawk-moths," on account of the swiftness of their flight, and "sphinxes," because the caterpillars from which they develop have a curious habit of remaining motionless, with their heads and the forepart of their bodies raised in an attitude a little like that of the crouching-sphinxes of old Egypt. A few hawk-moths fly by day, but most species rove abroad during the morning and evening twilight, when they may be seen flit-ing with great swiftness from flower to flower (Fig. 54).
Sphinx ligustri. Sphinx convolvuli.
Fig. 54. - Nocturnal guests of the honeysuckle. (From Tiguier's Insect World).
The honeysuckles blow just at the time of year when these moths are most numerous, and they offer a rich feast to their chosen guests, for the freshly-opened flowers are filled to the middle of their slender tubes with nectar.
The pollen-grains of the honeysuckles are rounded, somewhat sticky, and are covered with small, sharp points (Fig. 55). They adhere to the hairy bodies of the night-moths, and thus are carried to the pistils of other flowers.
Fig. 55. - Pollen of the honeysuckle. (Magnified).
On warm, calm evenings the honeysuckles' visitors are so numerous that by morning all the flowers have had their pollen entirely removed.
But after cold and windy nights the anthers still retain much of their golden store.
This will be carried away in daylight hours by butterflies or humming-birds.