Worcester daily spy. [volume] (Worcester [Mass.]) 1850-1888, 1872-05-30

Dana, LID, Professor OF Geology and Mineral
ogy in Yale College, etc. New York Dodd &
Mead, publishers. This is magnificent book,
the paper, type, binding, and mechanical execu
ton throughout, being very fine, and the con-
tents presenting the most complete and trust
worthy account of corals, coral makers, coral
islands, and coral reefs, that has ever appeared.
The observations and studies of Professor Dana,
while connected with the Wilkes Exploring Ex-
petition from s3s to 1912, form the basis of the
work; bat he has used all the facts and other
results of exploration, which have been added
during the last thirty years. Mr. Darwin's
book on coral reefs, Published in 1912, is the
only work that can be properly cassed with it;
but Mr. Darwin prepared his work more than
thirty years ago, and did not discuss the whole
subject; and, of course, he could not give the
results of discoveries and studies made since
that time. Whoever wishes TO know all that can
be known, at present, about corals and coral
formations, must study this admirable work of
Professor Dana. He says, in the preface, that
he has aimed TO make it popular "without a
sacrifice of scientific precision, or, on the main
topic, of fullness;" and he was able to do this
successfully. The illustrations, which are APP
propriate and abundant, are remarkably fine,
all the designs being from nature, by very COM
petent artists, and the engraving unusually ex.
ceent and beautiful.
The work fills a large octave of 1893 pages. 1t
is divided into six chapters and an appendix =,
the headings being as follows: Corals and
Coral Makers Structure of Coral Reefs and
Isa nds; Formation of Coral Reefs and Islands.
and Causes of their Features; Geographical Dis
tribution of Coral Reefs and Islands; Changes
of Level in the Pacific Ocean; Geological Con-
illusions. But these headings give an imperfect
notion of the fullness and variety Conformation
with which every part of the subject is presented.
The Appendix has short papers on Geological
Time, "Radiates,' and "Protozoans," followed
by an isotherma chart of the oceans, and other
matters The first chapter describes the crea-
lures by which coral is made. There are four
kinds of such creatures, but the most important,
the reef and island builders, are the polyps, OF
which there are several varieties. They are
"true radiates," and there are branches of the
family which do not make coral. The actnoid
polyps "vary immensely in size, from an eighth
of an inch in the diameter of the disk to over a
foot" The poyps do not manufacture coral;
the coral is natural secretion consisting of car
Donate of lime. 1t is, like the shell of the mol
lusc or the bones of fish, produced naturally
and necessarily. This power of secretion be-
longs emiVently to the lowest forms of life In
the coral makers it appears to be something
wonderful something as difficult to explain fully
as the origin of life ITSELF
D.
require a tropical temperature. They can ap-
pear only in seas where the temperature of the |
water, in the coolest season, is not below 6S de- |
grees. The boundary lines Of coral are between |
20 and 80 degrees of latitude, on each side of the
equator; but they have remarkable textures |
caused by currents and other influences, which |
bend them toward the equator, in some places, |
In this way the Galapagos Islands, situated |
only half degree south of the equator, are ex-
cuded from the coral sea. In mid-ocean, the |
coral seas are about sc degrees wide. In the |
Pacific, on the west coast of America, they are
rs degrees wide, while on the Asiatic side the /
width is AZ degrees. In the Atlantic, on the |
African coast, the coral region is only 10 de- |
grees wide, but on the American side it is As de-
grees wide. 1t must be kept in mind, however,
that there are textures which make the boundary
lines irregular. Thus the earth is belted by a
coral zone, which, in extent, corresponds very |
nearly TO the tropics. Throughout this zone, in |
the Atlantic, Pacific and Indian oceans, the |
coral formations appear wherever congenial |
sites for their growth exist. The Pacific APP |
pears to furnish the finest and most extensive
of these formations; and in this ocean both |
Professor Dana and Mr.. Darwin seem to have |
found their best opportunities for studying |
them.
The coroutuDl rUbrUnl, or precious coral ofcom-
merce, comes chiefly from the Mediterranean, al
though il will doubtless be found and gathered in
other parts ofthe zone. 1t red varying in shade
from crimson TO rose color. IL is gathered from
the rocky bottom along the shores Of the Medit-
erranean or near its islands, at depths of from
twenty-five to fifty feet, Though it sometimes
occurs even down to 1000 feet" Gathering this
coral is a business Of considerable importance.
There are important coral fisheries off the coast
Of Southern Italy, Sicily, Corsica, Sardinia and
Algeria, and in the gulf of Gaeta and the straits
of Bonifacio. In 1858, these fisheries yielded
10000 pounds of coral. The rose coored coral
commands the highest price in the market be-
cause it is the rarest. But we cannot reproduce
here nor even suggest all the valuable informa-
ton found in Professor Dana's book, which is
full OF interest for those whose tastes lead them
to study the subject. For sale by Grout & Put
nam.