52 THE PROBLEMS OF THE DEEP SEA n 



1,000 fathoms, all " in a peculiar condition from 

 the expansion of the air contained in their bodies. 

 On their relief from the extreme pressure, their 

 eyes, especially, had a singular appearance, pro- 

 truding like great globes from their heads." 

 Bivalve and univalve mollusca seem to be rare at 

 the greatest depths; but starfishes, sea urchins, 

 and other echinoderms, zoophytes, sponges, and 

 protozoa abound. 



It is obvious that the Challenger has the 

 privilege of opening a new chapter in the history 

 of the living world. She cannot send down her 

 dredges and her trawls into these virgin depths of 

 the great ocean without bringing up a discovery. 

 Even though the thing itself may be neither 

 " rich nor rare," the fact that it came from that 

 depth, in that particular latitude and longitude, 

 will be a new fact in distribution, and, as such, 

 have a certain importance. 



But it may be confidently assumed that the 

 things brought up will very frequently be zoo- 

 logical novelties ; or, better still, zoological 

 antiquities, which, in the tranquil and little- 

 changed depths of the ocean, have escaped the 

 causes of destruction at work in the shallows, and 

 represent the predominant population of a past 



It has been seen that Audouin and Milne 

 Edwards foresaw the general influence of the 

 study of distribution in depth upon the interpreta- 



