THE PHOSPHOKESUENCE OF THE DEEP. 4:tf 



fathoms, were most brilliantly phosphorescent. In some places 

 nearly everything brought up seemed to emit light, and the 

 mud itself was perfectly full of luminous specks. The alcyo- 

 narians, the brittle-stars, and some annelids were the most 

 brilliant. The Pennatidse, the Virgulariae, and the Grorgoniee 

 shone with a lambent white light, so bright that it showed 

 quite distinctly the hour on a watch, while the light from 

 Ophiacantha spinulosa was of a brilliant green, coruscating 

 from the centre of the disk, now along one arm, now along 

 another, and sometimes vividly illuminating the whole outline 

 of the star-fish. While the Ophiacantha shines like a star of the 

 most vivid uranium green, the sea-pen (Pavonaria quaohrangu- 

 laris) is resplendent with a pale lilac phosphorescence like the 

 flame of cyanogen gas, not scintillating like the green light of 

 Ophiacantha, but almost constant, sometimes flashing out at 

 one point more vividly, and then dying gradually into com- 

 parative dimness, but still sufficiently bright to make every 

 portion of the polyp visible. 



Such numbers of the Pavonaria were brought up at one haul 

 of the dredge in the Sound of Skye, that the " Porcupine " had 

 evidently passed over a forest of them. While the darkness of 

 winter frowns over the surface of the Northern Atlantic, the 

 animated shrubs at its bottom are thus glowing with light, and 

 a kind of magical day prevails in depths which were supposed 

 to be shrouded with perpetual night. But it might have been 

 better for many of the luminous denizens of the abyss if a more 

 obscure existence had been their lot; for in a sea swarming 

 with predaceous crustaceans with great bright eyes phosphor- 

 escence must surely be a fatal gift. 



Off the coast of Portugal there is a great fishery of sharks 

 (Centroscymnus Ccelolepis), carried on at a depth of 500 

 fathoms. If an animal so highly organised as a shark can thus 

 bear without inconvenience the enormous pressure of more 

 than half a ton on the square inch existing at lhat depth, it 

 is a sufficient proof that the pressure is applied under circum- 

 stances which prevent its affecting it to its prejudice, and there 

 seems to be no reason why it should not tolerate equally well 

 a pressure of one or two tons, or why many other fishes — though 



F F 2 



