tJie Animals of the Deep 8eas. 195 



bodies ; and so long as this has not been done we must refuse 

 them this name. 



Gwyn Jeffreys derives the decomposed organic mass at the 

 bottom of the sea from animals which have sunk down from 

 the surface ('Nature,' Dec. 9, 1869). Maury expresses him- 

 self similarly in his ' Physical Geography of the Sea ' (edition 

 1869, § 617) :— " The Ocean," he says, " swarms with living 

 creatures, especially between and near the tropics. The re- 

 mains of their myriads are carried on and collected by the 

 currents, and in course of time deposited like snow-flakes on 

 the bottom of the sea. This process, going on for centuries, 

 has covered the depths of the ocean with a mantle of organisms 

 as delicate as hoarfrost and as light as down in the air"*. 



These statements of Maury's were so far confirmed by 

 Wallich, that, in those places where few or no Foraminifera 

 lived, he found a thin layer of an organic deposit, measuring 

 from half an inch to an inch in thickness (North-Atlantic 

 Sea-bed, p. 138). 



All these attempts to explain the origin of the organic 

 material at the sea-bottom leave unconsidered another way by 

 which certainly great masses of organic and especially vege- 

 table nutritive material are constantly reaching the sea- 

 bottom. 



In the first volume of the ' Fauna der Kieler Bucht,' Dr. 

 H. A. Meyer and myself have divided the bottom of this small 

 Baltic gulf into the regions of the sandy strand, the green 

 Zostera^ the dead and decaying Zostera, the red Alg^, and 

 the black mud. The regions of the living and decaying plants 

 occupy the narrow slopes which fall from both shores towards 

 the depths. The black mud is a fine pasty mass which occu- 

 pies the wide deeper part of the valley of the gulf in so thick 

 a layer that it is not possible to penetrate it entirely with 

 dredges. The sm-face of the mass of mud is an almost regular 

 plain with a slight inclination towards the opening of the 

 gulf; near the town it is 6 fathoms below the surface, and 

 sinks gradually in a distance of two miles to a depth of 10 

 fathoms. All lines drawn upon this inclined plane from one 

 side of the bay to the other are almost entirely straight. This 

 flatness of the bottom is caused by the constant descent of 

 sinking materials from the slopes on each side. In this way 

 the deep sea-bottom receives annually a fresh supply of or- 

 ganic matters. The plants which have grown in the higher 



[* This source of the nutriment of deep-sea animals was indicated as 

 the most probable one by the Translator, in a notice of Dr. Wallich's 

 ' North-Atlantic Sea-bed,' Ann. & Mag. Nat. Hist. 1862, ser. 3. vol. x. 

 p. 383.1 



14* 



