II THE PROBLEMS OF THE DEEP SEA 45 



imprison ; and, now that the trawl can be success- 

 fully worked at the greatest depths, it may be 

 expected to supersede them ; at least, wherever 

 the ground is soft enough to permit of trawling. 



It is obvious that between the dredge, the trawl, 

 and the tangles, there is little chance for any 

 organism, except such as are able to burrow 

 rapidly, to remain safely at the bottom of any part 

 of the sea which the Challenger undertakes to 

 explore. And, for the first time in the history of 

 scientific exploration, we have a fair chance of learn- 

 ing what the population of the depths of the sea is 

 like in the most widely different paits of the world. 



And now arises the next question. The means 

 of exploration being fairly adequate, what forms 

 of life may be looked for at these vast depths ? 



The systematic study of the Distribution of 

 living beings is the most modern branch of Biolo- 

 gical Science, and came into existence long after 

 Morphology and Physiology had attained a con- 

 siderable development. This naturally does not 

 imply that, from the time men began to observe 

 natural phenomena, they were ignorant of the fact 

 that the animals and plants of one part of the 

 world are different from those in other regions ; or 

 that those of the hills are different from those of 

 the plains in the same region; or finally that 

 some marine creatures are found only in the 

 shallows, while others inhabit the deeps. Never- 

 theless, it was only after the discovery of America 



