a2 THE DEPTHS OF THE SEA. (CHAP. I. 
that it seemed probable that this gradual deposition 
of a fine 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 
Fic. 2.—Globigerina bulloides, DOrpIGNy. 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 
