346 NATURE AND MAN. 



decomposing state that animals having a large absorbent surface, 

 and requiring but a small proportion of solids in their food, might 

 be sustained by simple imbibition. And an adequate provision for 

 the continual restoration of such material to the ocean-waters 

 seemed to be made by the surface-vegetation which fringes almost 

 every sea-margin, and which occasionally extends itself over large 

 tracts in the open ocean, as, notably, in the Sargasso Sea. But 

 the Challenger researches have thrown a new light on this 

 question, by showing that the animals of the deep sea are largely 

 dependent for their food upon the minute organisms and the 

 debris of larger ones which are continually falling to the bottom 

 from the upper waters. 



" This debris (says Mr. Moseley) is no doubt mainly derived 

 " from the surface Pelagic flora and fauna, but is also to a large 

 " extent composed of refuse of various kinds washed down by 

 " rivers, or floated out to sea from shores, and sunken to the 

 " bottom when water-logged. The dead Pelagic animals must fall 

 " as a constant rain of food upon the habitation of their deep-sea 

 " dependants. Maury, speaking of the surface Foraminifera, 

 " wrote, ' The sea, like the snow-cloud, with its flakes in a calm, 

 " ' is always letting fall upon its bed showers of microscopic shells.' 

 " It might be supposed that these shells and other surface- 

 " animals would consume so long a time in dropping to the 

 " bottom in great depths, that their soft tissues would be decom- 

 " posed, and that they would have ceased to be serviceable as 

 " food by the time they reached the ocean bed. Such, however, 

 " is not the case, partly because the salt water of the sea exercises 

 " a strongly preservative effect on animal tissues, partly because 

 " the time required for sinking is in reality not very great." — 

 Notes by a Naturalist, p. 582. 



Of this Mr. Moseley assured himself by an experimental test, 

 which indicated that the dead body of a floating salpa might sink 

 to a depth of 2000 fathoms in little more than four days, whilst 

 its body might remain for a month so far undecomposed as to be 

 serviceable as food to deep-sea animals. As land was neared, 

 moreover, many interesting proofs were obtained of the feeding 

 of deep sea animals on debris derived from the neighbouring 

 shores. 



