ith his remarkable memoirs previously published, "On the
Distribution of the Mollusca and Radiata of the Aegean Sea," and "On the
Zoological Relations of the existing Fauna and Flora of the British
Isles," may be said to mark an era in the progress of human thought.

The dredging operations of the British Association committee were
carried on generally under the idea that at the 100-fathom line, by
which amateur work in small boats was practically limited, the zero of
animal life was approached--a notion which was destined to be gradually
undermined, and finally overthrown. From time to time, however, there
were not wanting men of great skill and experience to maintain, with Sir
James Clark Ross, that "from however great a depth we may be enabled to
bring up mud and stones of the bed of the ocean we shall find them
teeming with animal life." Samples of the sea-bottom procured with great
difficulty and in small quantity from the first deep soundings in the
Atlantic, chiefly by the use of Brooke's sounding machine, an instrument
which by a neat contrivance disengaged its weights when it reached the
bottom, and thus allowed a tube, so arranged as to get filled with a
sample of the bottom, to be recovered by the sounding line, were eagerly
examined by microscopists; and the singular fact was established that
these samples consisted over a large part of the bed of the Atlantic of
the entire or broken shells of certain foraminifera. Dr Wallich, the
naturalist to the "Bulldog" sounding expedition under Sir Leopold
M'Clintock, reported that star-fishes, with their stomachs full of the
deep-sea foraminifera, had come up from a depth of 1200 fathoms on a
sounding line; and doubts began to be entertained whether the bottom of
the sea was in truth a desert, or whether it might not present a new
zoological region open to investigation and discovery, and peopled by a
peculiar fauna suited to its special conditions.

In the year 1867, while the question was still undecided, two testing
investigations were undertaken independently. In America Count L. F. de
Pourtales (1824-1880), an officer employed in the United States Coast
Survey under Benjamin Peirce, commenced a series of deep dredgings
across the Gulf Stream off the coast of Florida, which were continued in
the following year, and were productive of most valuable results; and in
Great Britain the Admiralty, on the representation of the Royal Society,
placed the "Lightning," a sma