CHAPTER XV 
THE SCIENCE OF FOSSIL LIFE 
Ir gradually dawned on the minds of men that the crust 
of the earth is like a gigantic mausoleum, containing within it 
the remains of numerous and varied forms of life that for- 
merly existed upon the surface of the earth. The evidence 
is clear that untold generations of living forms, now pre- 
served as fossils, inhabited the earth, disported themselves, 
and passed away long before the advent of man. The knowl- 
edge of this fossil life, on account of its great diversity, is 
an essential part of biology, and all the more so from the 
circumstance that many forms of life, remains of which 
are exhibited in the rocks, have long since become extinct. 
No history of biology would be complete without an account 
of the rise and progress of that department of biology which 
deals with fossil life. 
It has been determined by collecting and systematically 
studying the remains of this ancient life that they bear testi- 
mony to a long, unbroken history in which the forms of both 
animals and plants have been greatly altered. The more 
ancient remains are simple in structure, and form with the 
later ones, a series that exhibits a gradually increasing com- 
plexity of structure. The study of the fossil series has 
brought about a very great extension of our knowledge 
regarding the age of the world and of the conditions under 
which life was evolved. 
Strange Views Regarding Fossils.—But this state of our 
knowledge was a long time coming, and in the development 
320 
