ONE 
DELVING INTO A PREHISTORIC RECORD 
K NOWLEDGE of what sort of vegetation covered 
the earth millions of years before man first appeared 
has reached an extraordinary accuracy. We now have 
information in this field which to many persons only a 
generation ago would have seemed unattainable. 
Just as we know much about the strange mammals 
and the incredibly gigantic reptiles—the long-extinct dino¬ 
saurs—that populated the earth in remote ages, so we 
now have a pretty good picture of the landscape amid 
which they lived; in other words, what kinds of trees 
and other plants surrounded them. The different varieties 
of plant life that flourished aeons ago, which great 
floods now and then buried where they grew, to be 
compressed and transformed into the coal we use today, 
are now so familiar to scientists that it is possible to 
reconstruct a whole forest of that period. The leaves 
and bark and seeds of the growing things can be repro¬ 
duced exactly as they were when this strange plant life 
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