Ashland tidings. [volume] (Ashland, Or.) 1876-1919, 1912-12-09
The Story of a Little Piece of Chalk.

The Story of Little Piece of Chalk.
A little piece of chalk tells an in
teresting history. To the unassisted
eye it looks simply like very loose
and open kind of stone, but if it is
ground down so thin that one can
see through it-until it is thin
enough to be examined with a mag
nifying glass-it will be found to be
made up of very minute granules,
! embedded in which are innumerable
bodies, some smaller and some larg-
er, but on a rough average not more
thap a hundredth of an inch in diam
eter, having well-defined shape and
structure. A cubic inch of some
specimens Of chalk may contain hun
dTeds of thousands of these bodies.
Each of the rounded bodies is made
up of a number of chambers, com
municating freely with one another.
These oddly shaped bodies are of
various forms, but one of the COM
monest is something like a badly
grown raspberry, being formed of a
number of nearly globular chambers
of different sizes congregated togeth-
er, They are the calcareous shells
Of foraminifera.
The beds of the oceans are covered
to a great extent with mud, embed
ded in which are millions upon mil
lions of skeletons of formanifera-
animals of the simplest imaginable
description. A foramanifer is, in
fact, mere particle of living jelly,
without defined parts of any kind
without mouth, nerves, muscles or
distinct organs, and manifesting its
vitality to ordinary observatioBonly
by thrusting out and retracting from
all parts of its surface long filaments
which serve for arms and legs. Yet
this creature is capable of feeding,
growing and multiplying; of separat-
ing the small proportion of carbonate
of lime which is dissolved in sea
water, and of building up that sub
stance into a skeleton or shell for
itself according to a pattern which
even the skilled artisan of the pres
ent day would find difficult to imi-
tate.
Some of the foraminifera are
known to exist only in the greatest
depths; others that float on the sur
face shower the bottom with their
minute shells as death comes. Most
of the foraminifera of the present
day are microscopic, but in few
species the shell attains a diameter
of an inch or more.
In the study of geology the forami-
nifera are of great interest, as they
are found in all tn eformations, from
the oldest to the newest, and in many
places they make up the chief part of
great rock masses. Examples may
be cited in the chalk cliffs of Eng
land, the nummulitic limestones of
Egypt, and the Silurian beds of Rus
! sia.
The United States Geological Sur
vey has recently published, as Bulle-
tin 513, a report on Pliocene and
Pleistocene foraminifera from south
ern California, by Rufus Mather
Bagg, Jr. Que of the most signifi-
cant facts revealed by the study of
these fossils is that the deposits are
not of tropical or warm-temperate
origin, but are made up of types COM
mon in the north Atlantic ocean to-
day; some of the species correspond
to forms that inhabit both the south
Atlantic and south Pacific. The re-
port, which is technical in character,
may be had free on application to the
Director of the United States Geolog-
ical Survey at Washington, D. C.