22 THE DEPTHS OF THE SEA. [chap. i. 



that it seemed probable that this gradual deposition 

 of a line uniform organic sediment was almost 

 universal. 



Then the question arose whether the animals which 

 secreted these shells lived at the bottom, or whether 

 they floated in myriads on the surface and in the 

 upper zones of the sea, their empty shells falling 

 after death through the water in an incessant shower. 

 Specimens of the soundings were sent to the eminent 



Fig. 2.—Gloligerin.a bulloides, D'Orbigny. Highly magnified. 



microscopists Professor Ehrenberg of Berlin and the 

 late Professor Baily of West Point. On the moot 

 question these two naturalists gave opposite opinions. 

 Ehrenberg contended that the weight of evidence 

 was in favour of their having lived at the bottom, 

 while Baily thought it was not probable that the 

 animals live at the depths where the shells are 

 found, but that they inhabit the water near the 



