SCENERY AT GREAT DEPTHS 31 



miles from the Irish or American coast, we should 

 find that the character of the sea-bottom has com- 

 pletely changed. Here we should be on Rudyard 

 Kipling's 'great grey level plains of ooze.' All around 

 us would stretch a vast dreary level of greyish-white 

 mud, due to the tireless fall of the minute globigerina 

 shells mentioned above. This rain of foraminifera 

 is ceaseless, and serves to cover rock and stone alike. 

 It is probably due to this chalky deposit that so many 

 members of the 'Benthos' — a term used by Haeckel 

 to denote those marine animals which do not swim 

 about or float, but which live on the bottom of the 

 ocean either fixed or creeping about — are stalked. 

 Many of them, whose shoal-water allies are without 

 a pedicel, are provided with stalks ; and those whose 

 shallow-water congeners are stalked are, in the depths, 

 provided with still longer stalks. Numerous sponges 

 — the alcyonarian Umbellula, the stalked ascidians, 

 and, above all, the stalked crinoids — exemplify this 

 point. 



Flat as the Sahara, and with the same monotony of 

 surface, these great plains stretch across the Atlantic, 

 dotted here and there with a yet uncovered stone or 

 rock dropped by a passing iceberg. In the deeper 

 regions of the ocean — where, as we have already seen, 

 occasional pits and depressions occur, and great ridges 

 arise to vex the souls of the cable-layers — the globi- 

 gerina ooze is replaced by the less soluble siliceous 

 shells of the radiolarians and diatoms. The former 

 are largely found in pits in the Pacific, the latter in 

 the Southern Seas. But there is a third deposit which 

 occurs in the deeper parts of the ocean — the red clay. 

 This is often partly composed of the empty siliceous 

 shells just mentioned ; but over considerable areas of 

 the Pacific the number of these shells is very small, 

 and here it would seem that the red clay is largely 

 composed of the 'horny fragments of dead surface- 



