42 
Tne American Geologist. 
January, 1896 
story of the earth’s life written in natural hieroglyphics. 
They set themselves at once to the task of reading this new 
language and translating its terms not, it is true, into years 
but into an orderly chronology. And just as the Egyptian 
history has gradually unfolded itself before us as the obelisks 
and other monuments have yielded up their secrets until now 
almost any tablet that is found can at once be referred to its 
approximate date, so the life history of the globe, imperfectly 
interpreted as it yet is, has become so well known that the 
paleontologist feels little hesitation in referring approxi¬ 
mately to its proper horizon an}^ specimen that comes before 
him. A certain facies which strikes the practiced eye at a 
glance and instinctively suggests their position characterizes 
the fossils of every era. There is no real repetition of pattern. 
As no sovereign has ever repeated the coin or medal of 
any predecessor so nature never reverts to a type that has 
once passed away. As Sir Lyell once observed, “ she makes 
her casts and then she breaks the mould.” Nor is there any 
counterfeiting. Similar conditions may occasionally recall 
similarity on some points, but an exact or colorable imitation 
of any one of these “medals of creation ” is unknown. 
It only followed then to associate the fossils with the rocks 
containing them so that when one is known the other could be 
inferred. This has been done and now it is easy to determine 
within very narrow limits the date of a stratum from an ex¬ 
amination of the fossils which it yields. The wonderful ad¬ 
vantage "which was thus conferred upon geology needs no 
lengthened explanation. Instead of investigating with great 
labor the stratigraphic relations of the strata in any land in 
which he is travelling the geologist seeks to collect as many 
fossils as he can find, in full confidence that on his return he 
or some one more skilled in the science will be able to read 
out of them the date of the rocks that yielded them. 
It will at once occur to the thoughtful reader, even if not a 
geologist, that it is of the very first importance that the stan¬ 
dard of reference be absolutely correct. Hence the faunas of 
the different strata must be compiled from regions in which 
little or no disturbance has taken place. If the rocks have 
been displaced it may be impossible to determine correctly 
their original relation and naught but confusion can ensue. 
