Evening star. [volume] (Washington, D.C.) 1854-1972, 1928-06-24

are said to be excellently preserved.
Meanwhile the life conditions of the
pre- Cambrian must be reconstructed
largely on the evidence afforded by
the Cambrian. A half billion years
ago the world in which the trilobites
crawied in the shallow water was
strangely different place from the world
of today. 1t was probably, as the
picture is drawn by DR.. Clark, an
extremely calm temperate world.
Weather. in the preSent-day sense OF
the word had not been born. The
majority of the Cambrian life forms,
close relatives of which are alive to-
day, have been found in shore rock
deposits. whereas their present de-
ScendantS are found in the depths of
The sea. where no disturbances or
changes of temperature are likely.
Now, the original seas. DR.. Clark
holds, were not salt. They have been
made salt by deposits washing into
them from the land through countless
generations, and arc growing more
salty. In the Cambrian. he believes,
the salt deposits in the water were so
much less than those at present that
the fact explains very well the startling
differences in conditions that enabled
these ancient life forms to flourish
over wide areas. All through the ages
the water from the rains percolating
through the grounds and collecting in
rivers running to the sea has been car
rying to the latter the salts which It
has taken from the land. while In its
evaporation from the surface OF the
sea to fall again upon the land as rain
it has left the salts behind,
Comparison Of Fauna.
He saws; An increase In the amount
of salts dissolved in water diminiSheS
the vapor pressure. Thus the Saltier
the sea, the less will be the evaporation
from Its surface, and hence the greater
proportion of the earth's water held
permanently in the ocean basins. as
compared to the water In the lakes.
ponds and rivers and to the water vapor
we're of fresh water their surface would
be far below the present level and nu-
merous land connections would appear
by which general interchange OF
faunaS now anconnected would be pos
sible. This water taken from the sea
would greatly increase the lake and
marsh areas on the land, and at the
same time result IN more or less extern
sively blanketing the earth with clouds.
An extensive envelope OF clouds about
the earth would have two most impor-
tdttN NutASCQdNktNNSs Ala bAAC AAsS PAuNNA
the suns heat would be far more equally
distributed There would be no frigid
poles nor superheated tropic none, Hot
and cold regions would be small and
localized, and would occur only where
the sun shone through the clouds In
the second place, an equality OF tenn
perature on the earth'S surface. or even
q fair approximation of 1t. coupled with
fresh-water seas, would mean a mini
mum of atmospheric circulation and q
general state OF calm unhroken by
storms such as we know today. Wave
action would be very slight and there
would be no destructive surf line. Ocean
currents would be very slow,
THE real difference between the
fauna of the oldest rocks and the fauna
of the recent seas. on close examination.
seems TO be not SO much real differ
ence In the animal types themselves as
an apparent difference resulting from
more extensive land connections. more
equahle distribution of the suns heat,
more tranquil conditions on land and IN
the sea and more extensive epicontI-
mental waters These four factors are
capable Of very simple explanation. on
the basis Of the eser-incrcasing saitiness
OF the sea-
Are Better Preserved.
There Is no certainty that Cambrian
and pre- aInhrian life was confined 70
better chance III pruseryM after death.
when their bodies sink 10 the notion
lGAnsinuea On Third RegeA