As to the actual cause of these exhibitions of light, little is known. In the case of M. Fries, the luminosity was always observed between quarter past ten and quarter past eleven in the evening, and especially when the weather was sultry, and was seen to best advantage when the observers were not looking at the flowers directly. The light appeared in fitful flashes, similar to that seen about the other flowers mentioned, and was supposed to be electric. Mr. Haggern was also inclined to believe that the phenomenon observed by him was electric. The flame seen about the flower ignited, by the daughter of Linnæus, was caused, as suggested by Phipson, by the ignition of the inflammable atmosphere that envelopes the essential oil-glands of certain _Flaxinellæ_. Electric light has been observed in a plant allied to the palm, belonging to the genus _Pandanus_. When the spatha, or covering which envelopes the flowers, is ruptured, a crackling sound is heard, and a spark of light emitted. It is not impossible that the light of certain flowers is in some way attendant upon the escape of pollen. CHAPTER XVII. VEGETABLE LAMPS. One of the most remarkable and awe-inspiring phenomena of the ocean is the water-spout,--a lofty column composed of tons of water, whirling upward, lifted by the mighty force of the wind. From a distance the formation of a spout is an interesting sight. In my own observations, there has generally been a low-lying bank of dark lead-colored cloud to announce its coming. From this a sharp cone, seemingly of cloud, was seen to drop, and in a very few moments an attenuated pillar rose from the water directly beneath it. The two appeared to meet, and, the alliance consummated, the lofty column moved away with a greater or less velocity. Near proximity to them is not unaccompanied with danger; and I once found myself in the centre of four or five, which were moving slowly about. The wind almost entirely died away, so that had our boat been a large one, we would have been completely at the mercy of the aqueous giants; as it was, we lowered the sail, and taking the oars, succeeded in avoiding them all.