And here is another description, no less striking; not this time of a floating medusa, but of a small coral-zoophyte, about ten inches long, common in the Mediterranean and in the Atlantic:—
“Nothing can exceed the beauty of the elegant opaline polyps of this zoophyte when fully expanded, and clustered like flowers on their orange-coloured stalk; a beauty, however, almost equalled by night when, on the slightest irritation, the whole colony glows from one extremity to the other with undulating waves of pale green phosphoric light. A large bucketful of these Alcyonaria was experimentally stirred up one evening, and the luminosity evolved produced a spectacle too brilliant for words to describe. The supporting stem appeared always to be the chief seat of these phosphorescent properties, and from thence the scintillations travelled onward to the bodies of the polyps themselves.”[5]
[5] Corals and Coral Islands, by Dana.
Travellers in all ages have described the marvellous illuminations seen at night on the ocean surface; illuminations long a mystery to those who gazed with admiration. At times the whole sea is one blaze of light; and the ship cleaves her way through liquid silver, or crimson glory, through milky whiteness or flames of blue and red.
And the greater part, if not the whole, as we now know, is due to uncountable multitudes of jelly-creatures, floating close to the surface, each contributing its tiny share to the radiant sheen. Sometimes they are large enough to be visible to the naked eye, but more generally they are minute microscopic beings, far too small individually to be seen by us, yet apparent in the mass by their united brilliance.
If millions of their glowing lamps shine in ocean’s deeper parts, we need no longer marvel to find deep-sea animals with large and well-developed eyes.
While on this subject, it should be added that the Medusæ have not a monopoly of ocean-lamps. Other creatures share in the task of lighting up those midnight depths.
Not long since two new species of fishes were discovered off the Azores, both of which possessed delicate organs of light-giving power. In one of them the rows of tiny lamps could be used or hidden “at will”—allowed to shine upon the world around, or shut off by a thick dark skin, somewhat after the fashion of a policeman’s “dark lantern.” Cuttlefishes too have been found carrying natural lamps for sub-ocean use.
CHAPTER XX.
ARMOURED MYRIADS AND MONSTERS
“The Sea hath its Pearls.”—Longfellow.