Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-06-13

How One May See the History Of the world
nj a Glance.

Il
Mt a Glance.
rNHE VERY NOTION OF CRowprNG THE
u history Of the earth for thousands OF million
OF years into one room Of moderate sire seems
an absurdity, and yet that has been done at the
| Nanonai Museum. srAn reporter saw there,
within the space Of fifty feet square, the life
story of this terrestrial globe illustrated.
| You can never get geologist tn speak on
| this subject in terms Of years or centuries
His learning and observation have so impressed
upon his mind the immensely Of time that
separates the creation Of the world from the
present that he views IL as he would eternity. in
| the light Of q duration uncomfortable by the
human mind. Man is but creature Of yester-
day, the climax Of animal development con-
| templating surroundings unimaginably old, TO
which his relation is that Of the newborn
flower on the summit Of the hoary mountain
peak.
The geologist finds his history book in the
layers Of which the earths crest il composed
In places, as at Trenton, Nj, commissions Of
nature have turned the crust over and the lay
ers are exposed in section. like q slice Of Jelly
cake Just as you can tell Of what material the
cake Is composed by examining il on your
plate. the scientific investigator learns the
story OF life on the earth by the remains Of 1t
that he finds in the layers. or the enormous
extent of time required for the formation Of
the layers he can form . feeble estimate by
guessing at the immense periods necessary for
incl. deposit by water and by reckoning upon
the succession Of the animal forms which they
contain. Within the last few years human
knowledge in this direction has taken great
| strides In advance, and fossils representing
creatures that once were alive have been found
fha, uho ho.l h.,
hitherto imagined to be the limit Of such dis
coveries
ANCESTORS OF THE LOBSTER
Even at the lowest point in the layers thus
far reached animals are found which, incon-
ceivably ancient as they are. must have re-
quired millions Of millions of years for their de-
velopment. Most important among these are
the triiobites, somewhat resembling the
horseshoe crabs" of the present day and not
remotely related to the latter. They were the
ancestors of the Holsters and crabs being the
earliest forms OF crustaceans concerning which
any knowledge is had. In those DAYS they
swarmed over the earth in such numbers that
single block OF mud a foot square. hardened
INTO stone. at the museum contains q dozen of
them. all as perfect and lifelike If they had
peen crawling about at the fishmonger's this
morning. Doubtless they were good 70 eat II
there had been any one on hand TO eat them,
and specimens have been found as much as
foot and half long, What palmozoic salads
they would have made to be sure, Unfortu-
nately there are no trilobites in existence now
lhey attained their elimination in the coal
forming epoch, and subsequently died ont.
During that earliest age OF which anything
is known there existed some astonishing mol
lusks, nearly related to the pearly nautilus of
today. But they were straight like fence rails
and specimens Of them are on exhibition al
the museum. measuring nine feet and more
in length. Their shells were built on the sum-
mer-lOtel nau with n lima NJ
their entire length, but. like the nautilus. this
ancient animal occupied only the room at the
entrance, leaving the others as vacant as il it
were cold summer at O watering place. When
1t grows too big for the apartment it had for
some time occupied ii moved forward, adding
an extension to its shell for purposes of ac-
commodation and built up a wall behind it Of
mother-of-pearl by means of a secretion
exuded from its rear. The empty chambers
however. were all left connected BY a pneu-
matte tube and were filled with air. which
could be compressed or exhausted as the moi
lusk happened to want to sink or rise in the
water. II progressed by means Of tentacles
such as the nautilus uses for the same pur-
pose.
These and other sorts Of creatures in those
days would get caught in the mud now and
then, which would harden and preserve them
Tor all time. Their animal tissue would not
keep. of course, but limy or other such par
| ticles would take its place as wasted, SO that
Among such fossils at the museum is one of
the chambered shell mollusks Just described,
made by nature into what looks exactly like a
brass cast, though it is really of iron pyrite
No ,eweler could have reproduced the Original
object 80 exquisitelv. The trilobitcs like many
other inhabitants of the sea. had an outer coat
of material called ''chitine." which is SO indie
| structible that acids have no effect upon it,
Thanks to this, where enormous supe rincum-
bent pressure has smashed them in their in
closing plId In the ms hoir ,,.Sr
have been in many instances kept in the form
ing rock.
A GLASS SPONGE.
The trilobites, though they gave in at last
and vanished. were an enduring species. They
kept on while newer creatures, which they
doubtless looked down upon, appeared and
made a success of themselves. Among these
latter were sponges-notably ''glaso sponge"
OF exquisitely beautiful and glass-liks network
About this time came the crinoids. 1t must be
| remembered that millions of years separated
successive types in these ancient epochs; il is
hard to tell where new forms began and there
Is no possibility OF saying how they were con-
nected However, there are some things worth
mentioning respecting the crinoids of which a
few species still survive on the ocean bottom.
They resembled flowers more nearly than any
other animals of which anything is known
Certain varieties at present living are called
''sea lilies" They belonged to the sea- urchin's
laIully: tuey udu lOlLteu Stems Win rOOtlete
branching into the ground, and each stem was
surmounted by a fower-like bud with waving
arms OF varying colors. Great beds of
them must have existed in the seas, be-
cause in places on land that were once sea-
bottom great masses of rock have been found.
notably at Burlington, Iowa, which are COM
posed almost wholly of fossil crinoids. You can
dig them out there by the cubic foot What
gorgeously-t tinted gardens in the ocean depths
must have been formed by these animal plants
when they were alive. Many casts made by
nature OF these pseudo flowers Of long ago have
been found, as well as Of the trilobites. 1t is
very curious to see how nature, billions Of
years ago, performed this operation Of taking
casts, which man has sonewly learned, employ
ing usually the same material, namely, lime.
For example, Mr.. Trilobite gets buried in
the mud, which hardens into stone
water psrcolates through the stone
and washes out all the particles which
composed his corpus. This leaves q perfect
mold OF his form. But water carries carbonate
of lime, and this substance is deposited around
the inside Of the mold, gradually filling il up
until the latter has only to be broken in order
to reveal perfect cast Of Mr.. Trilobite, to be
respected and revered as the ancestor of the
lobster and the crab. Can anything be more
interesting Doubtless most of the trilobite
fossils obtained are merely the cast-off shells of
those vanished crustacea, which changed their
clothing presumably as often do their de-
scendants. But this surmise does not in all
probability apply to the numerous specimens
which are found coiled up, with head and tail
together-an attitude intended TO protect their
soft parts underneath. 1t is really almost ex-