230 CHALLENGER 



Very considerable areas of the ocean floor are composed of 

 ooze formed by countless millions of calcerous skeletons of micro- 

 scopic and macroscopic plankton which has lived its brief life near 

 the sea's surface, and having died there, sunk slow^ly to form this 

 deposit. At greater depths than 3000 fathoms or so the calcerous 

 deposits are no more and only the skeletons of silicate forms of 

 plankton remain, for the calcerous forms have been eroded away 

 during their long slow fall and have become once again an integral 

 part of sea water. But the silicate forms continue unscathed to the 

 great depths, where are found the skeletons of diatoms, the plants, 

 and radiolarians, the animals, which, with red volcanic dust which 

 has fallen upon the sea surface miles above, form the really deep 

 ocean deposits. 



Such a sample now lay secure in a pickle jar, and this the author 

 took home with him when he left the ship a month or so later 

 in November, 1951. Back in London, he made his way to that 

 ormolu building of many turrets which houses the British Museum 

 of Natural History in the Cromwell Road. It was the first of many 

 visits to this treasure-house, and he was taking the cherished deep 

 bottom sample to Dr. J, D. H. Wiseman, who is an expert in 

 such matters. To reach his lair a guide was followed who took 

 the author at once from the main hall, where stuffed elephants 

 stand with oversized statues of Darwin and Huxley, down to the 

 cellars beneath. Here they passed along a maze of corridors lined 

 with racks on which are stacked spare, and forgotten stuffed 

 animals, their horns, their hoofs, their heads and their bones, 

 like some nightmare Aladdin's cave. At last the guide reached a 

 locked door upon which he rapped with a conspiratorial air, and 

 they were admitted to Dr. Wiseman's presence. 



The small pickle jar looked insignificant as it was placed upon 

 the table among many other jars of more imposing size and con- 

 tent. But Dr. Wiseman's enthusiasm made up for this, and soon 

 he and his companions were inspecting the sample through micro- 

 scopes, searching for the skeletons of the planktonic animals and 

 plants which it contained, and which had once floated near the blue 

 surface of the far-away Pacific Ocean. 



The search for greater depths still goes on and the Marianas 

 Trench may not remain for long the deepest known part of the 



