Geological Contemporaniety and Persistent Types of Life | Page 4

all others; and if,
notwithstanding her steady devotion to her own progress, she can
scatter such rich alms among her sisters, it should be remembered that
her charity is of the sort that does not impoverish, but "blesseth him
that gives and him that takes."

Regard the matter as we will, however, the facts remain. Nearly 40,000
species of animals and plants have been added to the Systema Naturae
by paleontologic research. This is a living population equivalent to that
of a new continent in mere number; equivalent to that of a new
hemisphere, if we take into account the small population of insects as
yet found fossil, and the large proportion and peculiar organization of
many of the Vertebrata.
But, beyond this, it is perhaps not too much to say that, except for the
necessity of interpreting paleontologic facts, the laws of distribution
would have received less careful study; while few comparative
anatomists (and those not of the first order) would have been induced
by mere love of detail, as such, to study the minutiae of osteology, were
it not that in such minutiae lie the only keys to the most interesting
riddles offered by the extinct animal world.
These assuredly are great and solid gains. Surely it is matter for no
small congratulation that in half a century (for paleontology, though it
dawned earlier, came into full day only with Cuvier) a subordinate
branch of biology should have doubled the value and the interest of the
whole group of sciences to which it belongs.
But this is not all. Allied with geology, paleontology has established
two laws of inestimable importance: the first, that one and the same
area of the earth's surface has been successively occupied by very
different kinds of living beings; the second, that the order of succession
established in one locality holds good, approximately, in all.
The first of these laws is universal and irreversible; the second is an
induction from a vast number of observations, though it may possibly,
and even probably, have to admit of exceptions. As a consequence of
the second law, it follows that a peculiar relation frequently subsists
between series of strata, containing organic remains, in different
localities. The series resemble one another, not only in virtue of a
general resemblance of the organic remains in the two, but also in
virtue of a resemblance in the order and character of the serial
succession in each. There is a resemblance of arrangement; so that the
separate terms of each series, as well as the whole series, exhibit a
correspondence.
Succession implies time; the lower members of a series of sedimentary
rocks are certainly older than the upper; and when the notion of age

was once introduced as the equivalent of succession, it was no wonder
that correspondence in succession came to be looked upon as a
correspondence in age, or "contemporaneity." And, indeed, so long as
relative age only is spoken of, correspondence in succession 'is'
correspondence in age; it is 'relative' contemporaneity.
But it would have been very much better for geology if so loose and
ambiguous a word as "contemporaneous" had been excluded from her
terminology, and if, in its stead, some term expressing similarity of
serial relation, and excluding the notion of time altogether, had been
employed to denote correspondence in position in two or more series of
strata.
In anatomy, where such correspondence of position has constantly to be
spoken of, it is denoted by the word "homology" and its derivatives;
and for Geology (which after all is only the anatomy and physiology of
the earth) it might be well to invent some single word, such as
"homotaxis" (similarity of order), in order to express an essentially
similar idea. This, however, has not been done, and most probably the
inquiry will at once be made--To what end burden science with a new
and strange term in place of one old, familiar, and part of our common
language?
The reply to this question will become obvious as the inquiry into the
results of paleontology is pushed further.
Those whose business it is to acquaint themselves specially with the
works of paleontologists, in fact, will be fully aware that very few, if
any, would rest satisfied with such a statement of the conclusions of
their branch of biology as that which has just been given.
Our standard repertories of paleontology profess to teach us far higher
things--to disclose the entire succession of living forms upon the
surface of the globe; to tell us of a wholly different distribution of
climatic conditions in ancient times; to reveal the character of the first
of all living existences; and to trace out the law of progress from them
to us.
It may not be unprofitable to bestow on these professions a somewhat
more