The Rise and Progress of Palaeontology | Page 4

entire orders of animals of the existence of which we
should know nothing except for the evidence afforded by fossil remains.
With all this it may be safely assumed that, at the present moment, we
are not acquainted with a tittle of the fossils which will sooner or later
be discovered. If we may judge by the profusion yielded within the last
few years by the Tertiary formations of North America, there seems to
be no limit to the multitude of mammalian remains to be expected from
that continent; and analogy leads us to expect similar riches in Eastern
Asia, whenever the Tertiary formations of that region are as carefully
explored. Again, we have, as yet, almost everything to learn respecting
the terrestrial population of the Mesozoic epoch; and it seems as if the
Western territories of the United States were about to prove as
instructive in regard to this point as they have in respect of tertiary life.

My friend Professor Marsh informs me that, within two years, remains
of more than 160 distinct individuals of mammals, belonging to twenty
species and nine genera, have been found in a space not larger than the
floor of a good-sized room; while beds of the same age have yielded
300 reptiles, varying in size from a length of 60 feet or 80 feet to the
dimensions of a rabbit.
The task which I have set myself to-night is to endeavour to lay before
you, as briefly as possible, a sketch of the successive steps by which
our present knowledge of the facts of palaeontology and of those
conclusions from them which are indisputable, has been attained; and I
beg leave to remind you, at the outset, that in attempting to sketch the
progress of a branch of knowledge to which innumerable labours have
contributed, my business is rather with generalisations than with details.
It is my object to mark the epochs of palaeontology, not to recount all
the events of its history.
That which I just now called the fundamental problem of palaeontology,
the question which has to be settled before any other can be profitably
discussed, is this, What is the nature of fossils? Are they, as the healthy
common sense of the ancient Greeks appears to have led them to
assume without hesitation, the remains of animals and plants? Or are
they, as was so generally maintained in the fifteenth, sixteenth, and
seventeenth centuries, mere figured stones, portions of mineral matter
which have assumed the forms of leaves and shells and bones, just as
those portions of mineral matter which we call crystals take on the form
of regular geometrical solids? Or, again, are they, as others thought, the
products of the germs of animals and of the seeds of plants which have
lost their way, as it were, in the bowels of the earth, and have achieved
only an imperfect and abortive development? It is easy to sneer at our
ancestors for being disposed to reject the first in favour of one or other
of the last two hypotheses; but it is much more profitable to try to
discover why they, who were really not one whit less sensible persons
than our excellent selves, should have been led to entertain views
which strike us as absurd, The belief in what is erroneously called
spontaneous generation, that is to say, in the development of living
matter out of mineral matter, apart from the agency of pre-existing

living matter, as an ordinary occurrence at the present day-- which is
still held by some of us, was universally accepted as an obvious truth
by them. They could point to the arborescent forms assumed by
hoar-frost and by sundry metallic minerals as evidence of the existence
in nature of a "plastic force" competent to enable inorganic matter to
assume the form of organised bodies. Then, as every one who is
familiar with fossils knows, they present innumerable gradations, from
shells and bones which exactly resemble the recent objects, to masses
of mere stone which, however accurately they repeat the outward form
of the organic body, have nothing else in common with it; and, thence,
to mere traces and faint impressions in the continuous substance of the
rock. What we now know to be the results of the chemical changes
which take place in the course of fossilisation, by which mineral is
substituted for organic substance, might, in the absence of such
knowledge, be fairly interpreted as the expression of a process of
development in the opposite direction--from the mineral to the organic.
Moreover, in an age when it would have seemed the most absurd of
paradoxes to suggest that the general level of the sea is constant, while
that of the solid land fluctuates up and down through thousands of feet
in a secular