New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1879-07-19
LIFE OF THE SlLURIAN AGE
TIE PRIMoRDIAL PERIOD IN GEOLOGY.
BY S. w. FORD.

TIRE PRIMoRDIAL PERIOD IN GEOLOGY.
The rocks representing what is known as the
Prlmordial Period have long been regarded by ge-
olocists rs Of moro than ordinary interest In these
rocks we find the fossil remains of the Oldest GER
tarnly known forms of life that existed on our
globe; while the period itself was one SO oeepN
buried IN the remote past, that any fact OF iactS
calculated to make us better acquainted WIN lts
history have been eagerly welcomed. AS migh'
naturally be expected, these facts have an lihpor
tant bearing upon certain great questions tha' arc
still under al cusson. such as the origin OF species,
and the mode of genesis of the various forms OF
animal aud vegetable life that exist upon the earth
awe find 1t to-day. But interesting as this sub
;ect is Will content myself for the present with
only the foregoing brief reference to it, since IL APP
pears the better plan first to give the reader some
account of the rocks themselves and OF the relations
which they sustain to both older and newer de-
positS.
The stratlfed rocks of our globe, presenting to-
tai thickness of not far from twenty miles, nave
been found by BIOLOGISTS TO consist OF numooI VI
great natural groups, each OF when represents
great natural period of time IN the worlds geoogl-
cal history. To these periods the term age h"'
been given: thus, commencing with the newest
we have the age of man, or Quarternary age, man
here being the predominant form of life ana
characterIzing the age as one of mind and lntelh-
oence next the Mammalian Age, an age remarkaDie
for the number and variety of forms OF quadrupeuS
many of them of enormous bulk, that then roameu
the earth next the Reptilian Age the predominant
life of which was of the repulan type next the
Carboniferous Age, an age principally omar
acterIzed by the accumulation OF vast ue
posts of vegetable matter which subsequent
ly became converted into the coal OF COM
merce next the Devonian Age, or age OF hsh-
4 Of hRm
binary pattern then greatly predomnatng over all
other forms of life next the Saran Age. or age OF
,nolIusks the mOuscan life or that represented In
orr own time by the clam, oyster cuttle-flsh ana SO
on then greatly prepOnderatng and last OF all the
Archaan Age from ArChdiOS the beginning, IN whlch
no life is certainly known to have existed Inc
rocks Of the Archaan Age form the universal tounda
tiop or floor upon which all the subsequently
formed deposits are piled and the lacts SHOW tnaV
they were crystalzed, lexed, and, in many IN
stances raised up into mountain helghtS' anu oe-
came areas Of permanent dry land before the low
est beds of the Siurian Age were laid down. Re
posing when in their natural order. upon the up
turned beds of the Archean and forming the low
et beds Of the Surian are the rocks of the Primor
dial Period or as they ere sometimes collectively
STYLED the Primordial Zone.
About twenty-five years ago. a celebrated Euro
pean paleontologist, NJ Joachim Barrande, who has
been engaged for nearly lifetime IN studying the
siluran rocks and fossils occurring IN the vicinity OF
PRAGUE Austria, began TO direct the attention OF
biologists to the peculiar disunctneSs and unity OF
the fossil forms characterizing this bis frmordlm
zone as compared with those of the other silurlan
deposits Since that time this zone has been recog-
nized in a great many quarters OF the globe 1t oc-
purs at various places, including Troy and Reese
vile in the State of New-York in Vermont MasSa-
chusetts, New-Brunswck, Newfoundland and Can
ada in Wisconsin, Iowa, Texas aud several more
Westerly states; in Norway Sweden, England
SPAIN and in the Argentine Republic OF Sourh
America. Ii will thus be seen that the prmordIai
rocks are well-ngh worldwide IN their dlstrtDu-
Hop. And another fact worthy of notice in this
connection is that these rocks often differ much
from each other in different regions, as, from we'll
known geological principles we should have been
led to expect Thus in certain regions, the forma-
tion ia a sandstone in others sandstone and slate
in Others to these added limestone and pudding
stone. while in still others it may be wholly slate,
and so on. But the organic remains found in them
everywhere present the general types of struc-
ture thedifisrences between the forms found IN any
two given regions, the rocks of which occupy the
same or approximately the same level In the zone,
generally being mainly of a specific nature. Weare
now in a position TO inquire what the lie Oh 0he
primordial period really was.
In attempting to answer this question. may, first
of all state the leading fact that far as has vet
been deciphered the life of the period was all ma
rine. over some of the old arshean slopes certain
low forms of vegetation may have existed, but Oh
this geology mas no proofs while the evidence Is
equally strong that there were no songs or voices 10
be heard in the air. and animal forms as highly
organized as the fish to be in the sea. 1t is
with no small difficulty that the mind can be
brought 10 realize such state of things. The am
NAL life already represented four ont of the ivesub-
Kingdoms recognized in the animal world, since IT
embraced articulates, molusks, radates and prOto-
zoans or those types of animal life represented In
our own time by the lobster oyster, star-tish and
sponge respectively. The vegetable life consisted
wholly of s.a-weeds. The artculates appeared I'M
der the form of crustaceans and WORMS, the former
being mainly represented by single tribe called
the trilobies which has long since become extinct.
They were very numerous and of many different
kinds One kind the Pdradoriies has large head,
long many-jointed BODY the number of body-seg-
ments varying from sixteen to twenty, very small
tail or. pygdium, occasionally armed with long
spines and is sometimes met with in forms having
length of twenty inches or more, and width at
the head of nearly foot (See Fig. H. 1t is the
type of the majority of primordial trilobites.
Fig. IL