LWING LAMPS 239 



that live in shallow water, including certain corals, are also 

 luminous, giving off a greenish light. 



Some polyzoans have been described as luminous; but this 

 needs confirmation, at any rate regarding those that live along 

 the shores. Luminous sponges have also been recorded, but 

 there is doubt whether the light came from the sponge itself or 

 from the creatures on and in it. 



Occasionally in the East Indies near the shore the water 

 glows with a continuous uniform somewhat milky light which 

 is not affected by the movement of a ship. This is caused 

 by luminous bacteria in countless millions. 



The black and white water of the Arctic, the so-called feeding 

 ground of whales, is mainly made up of diatoms with which 

 are also found various pelagic animals. 



\\ hile it has no connection with phosphorescence, it may be 

 here remarked that the color of the Red Sea is due to a minute 

 alga or sea plant which forms huge patches of a blood red tint. 

 A similar phenomenon was described by Darwin on the coast 

 of Chile and Peru, where Mr. Agassiz also saw it. It occurs 

 also in the Gulf of Mexico, though here the long trains or 

 patches are of a dirty yellow color instead of brilliant red. On 

 one occasion Mr. Agassiz found this same plant coloring the 

 surface of the sea a dirty yellow for an area of about a quarter 

 of a mile in length by a hundred yards in width north of Cape 

 Hatteras. 



An illumination, uniform in color, somewhat similar to the 

 bacterial, but on examination seen to arise from myriads of 

 minute sparklets, generally observed in a somewhat ruffled 

 sea and best seen along the sides of a moving ship, origi- 

 nates according to Steuer usually from flagellate infusorians. 



Vanhoffen has remarked that the small sparks of the in- 

 fusorians and the minute crustaceans and medusae are to the 

 flashes of the large medusae and the Pyrosomas as the small 

 stars in the sky are to the full moon passing through light 

 clouds. 



On our New England coast in the late summer and in early 



