ormous in amount and positive in
character. Therefore, if I do not further enlarge upon the evidence
which we here have, as it were _en masse_, it is only because I do not
feel that any words could add to its obvious significance. It may best
be allowed to speak for itself in the millions of facts which are
condensed in this tabular statement of the order of succession of all
the known forms of animal life, as presented by the eminent
palaeontologist, Professor Cope[17].

[17] For difficulties and objections, see Appendix.

Or, taking a still more general survey, this tabular statement may be
still further condensed, and presented in a diagrammatic form, as it has
been by another eminent American palaeontologist, Prof. Le Conte, in his
excellent little treatise on _Evolution and its Relations to Religious
Thought_. The following is his diagrammatic representation, with his
remarks thereon.

When each ruling class declined in importance, it did not perish,
but continued in a subordinate position. Thus, the whole organic
kingdom became not only higher and higher in its highest forms, but
also more and more complex in its structure and in the interaction
of its correlated parts. The whole process and its result is
roughly represented in the accompanying diagram, in which A B
represents the course of geological time, and the curve, the rise,
culmination, and decline of successive dominate classes.

[Illustration: FIG. 59.--Diagram of Geological Succession of the
Classes of the Animal Kingdom. (After Le Conte.)]

I will here leave the evidence which is thus yielded by the most general
principles that have been established by the science of palaeontology;
and I will devote the rest of this chapter to a detailed consideration
of a few highly special lines of evidence. By thus suddenly passing from
one extreme to the other, I hope to convey the best idea that can be
conveyed within a brief compass of the minuteness, as well as the
extent, of the testimony which is furnished by the rocks.

* * * * *

When Darwin first published his _Origin of Species_, adverse critics
fastened upon the "missing-link" argument as the strongest that they
could bring against the theory of descent. Although Darwin had himself
strongly insisted on the imperfection of the geological record, and the
consequent precariousness of any negative conclusions raised upon