"When we consider the immense area over which this deposit is spread, the
depth at which its formation is going on, and its similarity to chalk,
and still more to such rocks as the marls of Caltanisetta, the question,
whence are all these organisms derived? becomes one of high scientific
interest.

"Three answers have suggested themselves:--

"In accordance with the prevalent view of the limitation of life to
comparatively small depths, it is imagined either: 1, that these
organisms have drifted into their present position from shallower waters;
or 2, that they habitually live at the surface of the ocean, and only
fall down into their present position.

"1. I conceive that the first supposition is negatived by the extremely
marked zoological peculiarity of the deep-sea fauna.

"Had the _Globigerinoe_ been drifted into their present position from
shallow water, we should find a very large proportion of the
characteristic inhabitants of shallow waters mixed with them, and this
would the more certainly be the case, as the large _Globigerinoe_, so
abundant in the deep-sea soundings, are, in proportion to their size,
more solid and massive than almost any other _Foraminifera_. But the fact
is that the proportion of other _Foraminifera_ is exceedingly small, nor
have I found as yet, in the deep-sea deposits, any such matters as
fragments of molluscous shells, of _Echini_, &c., which abound in shallow
waters, and are quite as likely to be drifted as the heavy
_Globigerinoe_. Again, the relative proportions of young and fully formed
_Globigerinoe_ seem inconsistent with the notion that they have travelled