better opportunities of arriving at just
conclusions. There are formations which yield their organisms slowly to
the discoverer, and the proofs which establish their place in the
geological scale more tardily still. I was acquainted with the Old Red
Sandstone of Ross and Cromarty for nearly ten years ere I ascertained
that it is richly fossiliferous; I was acquainted with it for nearly ten
years more ere I could assign its fossils to their exact place in the
scale. Nature is vast and knowledge limited, and no individual need
despair of adding to the general fund.

_II.--Bridging Life's Gaps_

"The Old Red Sandstone," says a Scottish geologist in a digest of some
recent geological discoveries, "has hitherto been considered as
remarkably barren of fossils." Only a few years have gone by since men
of no low standing in the science disputed the very existence of this
formation--or system, rather, for it contains at least three distinct
formations. There are some of our British geologists who still regard it
as a sort of debatable tract, entitled to no independent status, a sort
of common which should be divided.

It will be found, however, that this hitherto neglected system yields in
importance to none of the others, whether we take into account its
amazing depth, the great extent to which it is developed both at home
and abroad, the interesting links which it furnishes in the geological
scale, or the vast period of time which it represents. There are
localities in which the depth of the Old Red Sandstone fully equals the
elevation of Mount Etna over the level of the sea, and in which it
contains three distinct groups of organic remains, the one rising in
beautiful progression over the other.

My first statement regarding the system must be much the reverse of the
one just quoted, for the fossils are remarkably numerous and in a state
of high preservation. I have a hundred solid proofs by which to
establish the truth of the assertion within less than a yard of me. Half
my closet walls are covered with the peculiar fossils of the Lower Old
Red Sandstone; and certainly a stranger assemblage of forms has rarely
been grouped together--creatures whose very type is lost, fantastic and
uncouth, which puzzle the naturalist to assign them even to their class;
boat-like animals, furnished with oars and a rudder; fish, plated over,
like the tortoise, above and below, with a strong armour of bone, and
furnished with but one soli