The mirror. (Stillwater, Minn.) 1894-1925, 1915-03-04

age is seen in its boulder beds O
the southern hemisphere condition
existing in no other part of thu
world, in this age. and difficult Il
explain. The distinguishing feature
of age is seen in the plant life
Cambrian life here becomes extinc
and new types are introduced. FoI
the first time the Amphebia, clas
of Vertehates to which the froG
belongs, are here seen.
The Permian age and The Palace
zoic epoch closed with one of the
greatest commissions that ever heav
ed the earth's, crusf, a conyGis;cn i!
comparison with which those o.
Ordovician time were mere tremOrs
1T was not only revolution in re-
lief but in plant and animal life al
well. In the Mesozoic era new
plants and animal life arise, new
conditions. new outlines.
During the vast interval of Car.
boniferious.and perhaps, earlier the
Appalachian geosyncline had beer
sinking with many shifts and oscil.
lations, under the ever increasing
load of sediment, until the grea,
trough contained a thickness oi
thirty to fourty thousand feet OF
strata, and when the trough began
to yield to lateral compression exert.
ed by the sinking crust, it's con.
tanned strata were thrown up into
great folds, and overthrust faults
Thus, in place the sinking sea bottom
along the shores of the great inland
sea rose the Appalachian Mount
aims, exceeding the Alps in height
To the west, along the shores of
the old Colorado Island. areas OF
sea bottom in Carboniferous age
were thrown up into permanent land
The Messozic ear is separated iu-
three ages: the Triassic, Jurassic
and the Cretaceous. No era of the
worlds history stands out with such
distinguishing features as the Mes
sozoic, or age of Reptiles. We saw
in the Devonian, the age of fish, ,es
the Carboniferous, the age of coal,
but to far greater degree, is the
Messozoic the age of Reptiles.
Some of the largest and most for
midable creatures that ever existed
were of the reptilian order of Mess
ozoie time, and before the close,
had attained the most remarkable
growth and diversity and an extra
ordinary height of development -
Not only were they the dominant
form Of life on land and sea, but the
air. as we'll was navigated by them.
OF the twelve reptilian orders of
Messozoic time in the zenith of their
develop ment, but four, remaintoday
dwarfed and and pygmied. This
old volume of the earths' history
seems to add new life and color to
the fabulous exploits of Grecian he
roes andof Morse and Saxon war
riors.
Here birds and mammals first ap-
pear, rudimentary and primitive at
first, the former still retaining many
of the structural attributes of their
reptilian ancestory," but at the same
exhibiting remarkable strides in ev-
o1n+ion onI ~ :,
also, are here seen. and before the
close, had attained quite a consider
able development. 1t must not be
imagined that new folms suddenly
developed in some inexplicable
manner from older FORMS" but tho
the slow evolotion of countless ages.
Amphibia seen for the first time il,
Permian, here attain it's greatest
proportions, in the Stegocephalia
and then rapidly decline. leaving
but the frog and salamander to mark
the passage of a mighty order.
Plant life, consisting of the most
part. of Ferns, Horsetail Clubmoss,
exhibits marked modification from
those seen in Carboniferious coal
beds. Briefly, the Triassic age was
one of volcanic activity and unrest.
The disturbance which brot tn e
Appalachian Mountains into being
seems to have inaugurated as width
spead changes in the west. Oscil-
ating crust here and there, resulting
in changes of physical geography
are reflected in the character Of the
rocks constituting the different
series throughout the age.
To the west, marine conditions
prevailed, in the central region shall
low inland seas. aud along the east
ern section, arms of the sea extern
ded we'll up toward Can ada, filling
depressions resulting from form dis
turbances and converting the whole,
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