sufficient care, as the important discoveries made every year in Europe prove. No organism wholly soft can be preserved. Shells and bones
....... 1872 | will 1859 1860 1861 1866 1869 |
decay and disappear when left on the bottom of the sea, where sediment is not accumulating.
We probably take a quite We probably take a quite 1872 |
I believe we are continually taking a most 1859 1860 1861 1866 |
I believe we often take an 1869 |
erroneous view, when we
assume assume 1872 |
tacitly admit to ourselves 1859 1860 1861 1866 1869 |
that sediment is being deposited over nearly the whole bed of the sea, at a rate sufficiently quick to embed and preserve fossil remains. Throughout an enormously large proportion of the ocean, the bright blue tint of the water bespeaks its purity. The many cases on record of a formation conformably covered, after an
immense immense 1869 1872 | enormous 1859 1860 1861 1866 |
interval of time, by another and later formation, without the underlying bed having suffered in the interval any wear and tear,
seem explicable only on the view of the bottom of the sea not rarely lying for ages in an unaltered condition. The remains which do become embedded, if in sand or gravel,
will, will, 1872 | will 1859 1860 1861 1866 1869 |
when the beds are
upraised, upraised, 1872 | upraised 1859 1860 1861 1866 1869 |
generally be dissolved by the percolation of
rain-water charged with carbonic acid. rain-water charged with carbonic acid. 1861 1866 1869 1872 |
rain-water. 1859 1860 |
Some Some 1861 1866 1869 1872 |
I suspect that but few 1859 1860 |
of the
....... 1861 1866 1869 1872 | very 1859 1860 |
many
kinds of animals kinds of animals 1861 1866 1869 1872 |
animals 1859 1860 |
which live on the beach between high and low
water mark water mark 1861 1866 1869 1872 | watermark 1859 1860 |
seem to be rarely seem to be rarely 1861 1866 1869 1872 |
are 1859 1860 |
preserved. For instance, the several species of the Chthamalinæ (a sub-family
of sessile cirripedes) coat the rocks all over the world in infinite numbers: they are all strictly littoral, with the exception of a single Mediterranean species, which inhabits deep
water, water, 1861 1866 1869 1872 | water 1859 1860 |
and
this has this has 1869 1872 | has 1859 1860 1861 1866 |
been found fossil in Sicily, whereas not one other species has hitherto been found in any tertiary
formation; formation; 1872 | formation: 1859 1860 1861 1866 1869 |
yet it is
....... 1872 | now 1859 1860 1861 1866 1869 |
known that the genus Chthamalus existed during the
Chalk Chalk 1866 1869 1872 | chalk 1859 1860 1861 |
period. ↑1 blocks not present in 1866 1869 1872; present in 1859 1860 1861 | The molluscan genus Chiton offers a partially analogous case.
|
Lastly, many great deposits requiring a vast length of time for their accumulation, are entirely destitute of organic remains, without our being able to assign any reason: one of the most striking instances is that of the Flysch formation, which consists of shale and sandstone, several thousand, occasionally even six thousand feet, in thickness, and extending for at least 300 miles from Vienna to Switzerland; and although this great mass has been most carefully searched, no fossils, except a few vegetable remains, have been found. |