88 EXPEDITION OF THE "CHALLENGER" m 



lished in the proceedings of the Royal Society, 1 

 from which a quotation has already been made, 

 Professor Wyville Thomson says : 



" I had formed and expressed a very strong opinion on the 

 matter. It seemed to me that the evidence was conclusive that 

 the Foraminifera which formed the GloUgerina ooze lived on 

 the bottom, and that the occurrence of individuals on the surface 

 was accidental and exceptional ; but after going into the thing 

 carefully, and considering the mass of evidence which has been 

 accumulated by Mr. Murray, I now admit that I was in error ; 

 and I agree with him that it may be taken as proved that all 

 the materials of such deposits, with the exception, of course, of 

 the remains of animals which we now know to live at the 

 bottom at all depths, which occur in the deposit as foreign 

 bodies, are derived from the surface. 



* ' Mr. Murray has combined with a careful examination of the 

 soundings a constant use of the tow-net, usually at the surface, 

 but also at depths of from ten to one hundred fathoms ; and he 

 finds the closest relation to exist between the surface fauna of 

 any particular locality and the deposit which is taking place at 

 the bottom. In all seas, from the equator to the polar ice, the 

 tow-net contains GloUgerince. They are more abundant and of 

 a larger size in warmer seas ; several varieties, attaining a large 

 size and presenting marked varietal characters, are found in the 

 intertropical area of the Atlantic. In the latitude of Kerguelen 

 they are less numerous and smaller, while further south they are 

 still more dwarfed, and only one variety, the typical Globigerina 

 bulloides, is represented. The living Gflobigcrince from the tow- 

 net are singularly different in appearance from the dead shells 

 we find at the bottom. The shell is clear and transparent, and 

 each of the pores which penetrate it is surrounded by a raised 

 crest, the crest round adjacent pores coalescing into a roughly 



1 "Preliminary Notes on the Nature of the Sea-bottom pro- 

 cured by the soundings of H.M.S. Challenger during her cruise 

 in the Southern Seas, in the early part of the year 1874."- 

 Proceedings of the Royal Society, Nov. 26, 1874. 



