ve that the _Foraminifera_
which formed the _Globigerina_ 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.

[Footnote 8: "Preliminary Notes on the Nature of the Sea-bottom procured
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.]

"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 _Globigerinoe_. 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 _Globigerinoe_ 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 hexagonal network, so that the
pores appear to lie at the bottom of a hexagonal pit. At each angle of
this hexagon the crest gives off a delicate flexible calcareous spine,
which is sometimes four or five times the diameter of the shell in
length. The spines radiate symmetrically from the direction of the centre
of each chamber of the shell, and the sheaves of long transparent needles
crossing one another in different directions have a very beautiful
effect. The smaller inner chambers of the shell are entirely fil