240 OUR HERITAGE THE SEA 



these ultra-scientific days of ours there should be so 

 vast a portion of our globe as unknowable as space 

 itself, a very world peopled by the strangest forms of 

 life existing under the most extraordinary conditions 

 of pressure, lack of light and air, conceivable by us, is 

 enough to give the least imaginative mind among us 

 something to dwell upon with awe ; for it has no 

 parallel on the dry land or in the air. Above a very 

 thin film of atmosphere terrestrial life must cease, below 

 an equally thin stratum of earth it is the same, bat in 

 the ocean's depth we know that life everywhere 

 abounds, even in abysses which would submerge 

 Kinchinjanga or Aconcagua. From these profound 

 depths the trawls of the Challenger have drawn strange 

 forms of life, but there has always been a feeling that 

 these may not have come from the greatest depths; 

 and, in any case, when we remember the enormous area 

 of the ocean and the tiny space covered by the ship, 

 we must at once feel how trivial must be the know- 

 ledge gained by the most unremitting industry of 

 exploration. All our speculations as to the nature of 

 those gloomy profundities seem to fall lamentably 

 short of the possibilities of mysterious life abounding 

 there, and after dwelling upon them for a space the 

 mind recoils, baffled from the attempt to imagine what 

 the depths of the ocean must be like. We may, how- 

 ever, dwell with a certain complacency upon what man 

 has accomplished in spite of the difficulties attendant 

 upon deep-sea exploration, chief among which is the 

 truly wonderful feat of laying the submarine cables. 

 First of all, the careful laying off of a line of deep-sea 

 soundings from continent to continent, so that a rough 

 idea of the contour of the ocean-bed might be gained, 



