There are many living fish, phosphorescent; and, under certain conditions, by a rapid throwing off of luminous particles must largely contribute to the result.

Not to particularize this circumstance as true of divers species of sharks, cuttle-fish, and many others of the larger varieties of the finny tribes; the myriads of microscopic mollusca, well known to swarm off soundings, might alone be deemed almost sufficient to kindle a fire in the brine.
But these are only surmises; likely, but uncertain.
After science comes sentiment.
A French naturalist maintains, that the nocturnal radiance of the fire-fly is purposely intended as an attraction to the opposite sex; that the artful insect illuminates its body for a beacon to love.
Thus: perched upon the edge of a leaf, and waiting the approach of her Leander, who comes buffeting with his wings the aroma of the flowers, some insect Hero may show a torch to her gossamer gallant.
But alas, thrice alas, for the poor little fire-fish of the sea, whose radiance but reveals them to their foes, and lights the way to their destruction..