222 A DESCENT INTO PERPETUAL NIGHT 



My eyes became so dark adapted at these depths that 

 there was no possibiHty of error; the jet blackness of the 

 water was broken only by sparks and flashes and steadily 

 glowing lamps of appreciable diameter, varied in color and 

 of infinite variety as regards size and juxtaposition. But 

 they were never dimmed or seen beyond or through any 

 lesser mist or milky-way of organisms. The occasional, 

 evanescent, defense clouds of shrimps hence stand out all 

 the more strongly as unusual phenomena, and are quite 

 apart from the present theme. If the surface light is emit- 

 ted chiefly by Noctiluca and single-celled plants, the ex- 

 planation of its abyssal absence is easy, for all surface forms 

 of these groups have died out hundreds of feet overhead. 



A second thing which occurred to me as I sat coiled in 

 the bathysphere, more than half a mile down, was the fail- 

 ure of our powerful beam of light to attract organisms of 

 any kind. Some fled at its appearance, others seemed wholly 

 unconcerned, but not a single copepod or worm or fish 

 gathered along its length or collected against the starboard 

 window from which it poured. We sometimes kept the 

 lesser beam on for three minutes at a time, so there was 

 abundance of time for the plankton, which abounded in 

 all parts of the path of light, to feel and react to its influ- 

 ence. The reason for this demands far more study than I 

 have been able to give it. One factor is doubtless not only 

 lack of the rhythm of day and night, but the eternal ab- 

 sence of all except animal light. 



Even in this extremity of blackness I sensed the purity 



