They travel freely through the ocean depths, like fishes; and they sting sharply, like nettles. Yet they are neither.
Another name given to them is that of “Sun-fishes,” because in calm weather they often float close to the surface of the sea, as if delighting to bask in sunshine. One could almost imagine that, after the fashion of modern “luminous paint,” they are taking in sunlight, to carry stores thereof later into dark depths, for the benefit of less favoured comrades. But let a heavy storm arise, and swiftly these fragile creatures wend their way into the placid depths, beyond reach of wind and wave.
Many years ago a story was told of a certain farmer, who had heard that medusæ were particularly good as manure. He had large supplies of them carted to his land, with much expense and trouble. Not till later did he learn how small a part of the creatures consisted of anything but water; how easily he might have had the whole mass of them dried, and then carried by hand, at almost no cost.
Medusæ, as earlier stated, are of all sizes, from tiny translucent bags of liquid to huge discs of jelly-like substance, rivalling a man’s umbrella in diameter.
They are also of all kinds and shapes. Many of umbrella-shape have, in place of a handle, bundles of fleshy tentacles hanging down below, and thin streamers reaching to a length of a hundred feet. Some are more like saucers or bowls. Others of longer and narrower make have been likened to large thimbles. Some are ribbon-like beings, moving in graceful serpentine folds. Others have the outlines of elegant tubes. Many, again, are like little inverted delicate shrubs, or fairy-seaweed fronds, hanging downward. Some carry sail upon the surface of the water.
While all are of a more or less jelly-like substance, some are so frail and watery that they can only be lifted out of the sea in a pail. Any other mode causes them to drop to pieces.
But the most wonderful and beautiful characteristic of the jelly-fish is that of its self-illuminating power.
Here is a description of one kind, found in the Atlantic, near the coast of North America:—
“Objects of more exquisite beauty than some of these hydroid-medusæ do not perhaps exist. Each minute crystal chalice, with its beautifully curved outline, elongated delicate tentacles, gently coiling and uncoiling, and its slender proboscis which hangs like a lamp in the centre, lighting it with a soft phosphorescent glow, is the very type of delicate beauty, suggesting the wonders of fairyland.”[4]
[4] J. S. Kingsley.