Mont Blanc might be sunk without showing
its peak above water. Beyond this, the ascent on the American side
commences, and gradually leads, for about three hundred miles, to the
Newfoundland shore.

Almost the whole of the bottom of this central plain (which extends
for many hundred miles in a north and south direction) is covered by a
fine mud, which, when brought to the surface, dries into a grayish
white friable substance. You can write with this on a black-board, if
you are so inclined; and, to the eye, it is quite like very soft,
grayish chalk. Examined chemically, it proves to be composed almost
wholly of carbonate of lime; and if you make a section of it, in the
same way as that of the piece of chalk was made, and view it with the
microscope, it presents innumerable Globigerinae embedded in a granular
matrix.

Thus this deep-sea mud is substantially chalk. I say substantially,
because there are a good many minor differences; but as these have no
bearing on the question immediately before us--which is the nature of
the Globigerinae of the chalk--it is unnecessary to speak of them.

Globigerinae of every size, from the smallest to the largest, are
associated together in the Atlantic mud, and the chambers of many are
filled by a soft animal matter. This soft substance is, in fact, the
remains of the creature to which the Globigerina shell, or rather
skeleton, owes its existence--and which is an animal of the simplest
imaginable description. It is, in fact, a mere particle of living
jelly, without defined parts of any kind--without a mouth, nerves,
muscles, or distinct organs, and only manifesting its vitality to
ordinary observation by thrusting out and retracting from all parts of
its surface long filamentous processes, which serve for arms and legs.
Yet this amorphous particle, devoid of everything which, in the higher
animals, we call organs, is capable of feeding, growing, and
multiplying; of separating from the ocean the small proportion of
carbonate of lime which is dissolved in sea-water; and of building up
that substance into a skeleton for itself, according to a pattern
which can be imitated by no other known agency.

The notion that animals can live and flourish in the sea, at the vast
depths from which apparently living Giobigerinae have been brought up,
does not agree very well with our usual conceptions respecting the
conditions of animal life; and it is not so absolutely impossible as
it might at