CHAPTER XXXVII 
PALEOBOTANY 
503. The Scope of Paleobotany. The study of fossil 
plants, though of course a phase of botany, constitutes 
a science by itself, not only covering a special subject 
matter, but having its own methods (technique) , and pos- 
sessing a large literature. It is called paleobotany. One 
cannot pursue this study without a knowledge of the 
anatomy and morphology of living forms. This is neces- 
sary in order to interpret the meaning of plant fossils, 
which often occur only in small fragments of the entire 
plant. Moreover, one must have a good knowledge of 
at least the elements of geology, since fossils are found in 
rocks. One must not only know the geological age to 
which the fossil-bearing rock he studies belongs, but also 
something of the geological processes by which fossils, 
and even the rocks themselves, are formed. 
504. What is a Fossil? A fossil is any remains of a 
plant or animal that lived in a geological age preceding 
the present; these remains are preserved in rocks. 1 There 
are two methods of preservation, namely, incrustation and 
petrifaction. Incrustations are merely impressions or 
casts resulting from the encasement of the organ or 
organism in the rock-forming material. The tissue itself 
1 By an extension of the term we also speak of fossil footprints of ani- 
mals, fossil ripple marks, et cetera. The word fossil is derived from the 
Latin fodere (to dig), and originally signified anything dug up. 
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