THE 
AMERICAN NATURALIST 
Von. X XIX. October, 1895. 346 
THE FIRST FAUNA OF THE EARTH. 
By Josera F. James, M. D., M. Sc., F. G. S. A., ere. 
One of the most interesting questions with which the geolo- 
gist has to deal is the age of the earth. There is, how- 
ever, no subject that is wrapped in more profound obscurity, 
and yet probably none to which more attention has been 
given. Perhaps it may never be settled positively; but, as 
years roll on, and more and more facts come to light, specula- 
tions may be made with a greater amount of certainty. It 
may be possible, in the future, to say approximately how many 
centuries have elapsed since the earth assumed its present 
form, but, of course, it can be on/y approximate. Estimates 
vary now between one hundred million and five hundred 
million years, since the first rocks were laid down. 
While this matter still remains uncertain, there is another 
which was formerly, and still is, in much the same state. It 
is the beginning of life upon the earth. Geology is a young 
science, but her sister, Paleontology, is younger. Both are 
taking rapid strides forward, and, working hand in hand, they 
will eventually be able to tell us much of interest about this 
globe of ours. 
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