l82 ANIMAL LIFE OF THE DEEP SEA BOTTOM 



give it impetus) will flow right down to the bottom. In less than lOo 

 kilometres the depth falls by lo kilometres, from time to time in abrupt 

 drops, as shown in the diagram based on our echo-soundings (page 33). 

 Immense phenomena must take place here, and I think that this is a 

 possible explanation of why we found jagged stones and other rough bottom 

 material in the clay from the otherwise flat valley bottom. Apart from 

 this, the significant factor as far as animals are concerned is that fresh 

 masses of water containing oxygen are dragged into the deep, providing 

 their vital requirements of air to breathe . . . 



We now looked forward with a certain amount of confidence to the 

 approaching oceanic trenches. The next was the Sunda Trench, which 

 extends in an immense curve south of Java and westward towards Sumatra. 

 The greatest depths of a little over 7,000 metres lie south of Java, and 

 we made straight for them, as time was short and weather none too good — 

 the south-easterly wind and sea were strong at times and there was also some 

 current. We did not spend much time on sounding, as we found that the 

 configuration corresponded roughly to that of the Philippine Trench, with 

 steep valley sides and a narrow strip of level bed. Here we experienced 

 setbacks from the start, two sledge-trawls failing to reach the bottom and 

 a third coming up with a torn bag. Only the two attached small dredges 

 brought much bottom material, though it was good. There were five 

 starfishes, seven sea-cucumbers, some black corals, a bristle-worm, five 

 echiuroid worms, an amphipod, a tusk-shell, and 10 bivalves. We 

 then risked our large otter-trawl at 7,130 metres, keeping it on the 

 bottom for two hours and dragging it at a speed of a good 2.5 kilometres 

 an hour. We should have liked to drag it a little faster, but that would 

 have meant more wire to pay out and haul in, taking more time and 

 involving risk, so we confined ourselves to paying out 10,600 metres. 

 The result was the greatest haul that has ever been made from this depth. 

 First of all there were about 3,000 small deep-sea sea-cucumbers (Elpidia 

 glacialis) of the same species as we had caught in the sledge-trawl, plus 

 about 114 of a rather larger species (Periamma naresi). Our expert, Mr. 

 Bent Hansen^ has not been able to differentiate the Elpidias from some 

 found by the Ingolf Expeditions in the Arctic Ocean. It was an astonishing 

 catch in the southern hemisphere. There were also five amphipods and four 

 other crustaceans (Cumacea), and about 40 sea-anemones which we re- 

 cognized by their pale colour, though it is for the specialists to determine 

 their ultimate relationship with those of the Philippine Trench. Two bristle- 

 worms in this trawl certainly belonged to species closely related to 

 the one found in the Philippine Trench. Last but not least there was 



