The Meeker herald., 1897-06-05
the ACE OF THE WORLD.
II IL n.eA GREATER Tia. Has nssa
Supposed


Il h Much 0re.ter TIA. Has nssa
sspposed.
One of the questions considered by
Prof. E. B. Poulton in his presidential
address before the geological section
of the British association related to
the length of time required for the
development of animal life ON the earth
to its present condition. says Popular
Science Monthly; whether the pres
ent state Of archaeological and xooiog-
ical knowledge diminiahes or increases
the weight Of the opinion Of Darwin.
Huxley and Spencer. that the time
during which the geologists concinded
that the fossiliferous rocks had oeen
formed was utterly insufficient FOR or
Ganic evolution" The arguments OF
the physicists, derived from the sup
posed effect Of tidal action upon tne
length Of the day. and from the esti-
mated length of time occupied oy the
earth in cooling from an assumed tenn
perature TO its present condition. are
shown to have been proved Invalid as
bases for calculating the probable age
of the earth as life-bearing body.
The argument derived from tho sup
posed life of the sun has not yet been
ruled out and that gives maximum OF
500 600 900 years. Tho computation o1
III. time required for depOsiuns tho
geological strata gives q minimum oi
$4,000, 900 and maximum OF eSo.VVo,-
900 possibly 100000. .00o years
The authors inquiry as to how much
of the whole scheme of organic evoiu-
tion has been worked out In the time
during which the fossiliferous rocks
were formed does not deal with the
time required for the origin OF lie OF
for the development Of the lowest pc
ings with which we are acquaintea
from the flrst formed beings OF whicn
ve know nothing: but only with 30
much of the process Of evolution as
We can infer from the structure OF Nv
ing and fossil forms.
The comparison is made from a
studv of the evolution of the phyla. All
available evidence points to the ex-
treme slowness of progressive evolu-
tionary changes in the coelenterate
phyla. although the protozoa are even
more conservative. When We consider
| further on the five coelenterate phyla
that occur fossil we shall find that the
| progressive changes were slower and
| indeed hardly appreciable in the echi-
| noderms and gephyrea. as compared
whit the mollusca. appendiculata and
vertebrate, within these latter phyla
we have evidence for the evolution o.
higher groups, presenting more oi
less marked advance in organization:
Az a whole, the comparison Is quite
enough to necessitate very large IN
crease in the time estimated by TN
geologist. We can hardly escape TN
conclusion that, for the development
of the arthropod branches from com
mon chetopodlike ancestor ana tor TN
further development Of the classes o
each branch, period many times th
length of the fossiliferous series Is re
ouired. The evolution Of the ancesto
/ ----.---"s- .Aha hish>~ amfmAl pnyi
probably occupied as long a period a
that required fUr the usvs~ti~n whic'
subsequently occurred within the ply
lum. But the consideration Of tn
higher phyla which occur fossil, excep
the vertebrate, leads to the irresistibl
conclusion that the whole period II
which the fossiliferous rocks were lai,
down must be multiplied several time
for this later history alone The perio,
thus obtained requires to be again in
creased and perhaps doubled for tn
earlier history.