of
another and modified another and modified 1869 1872 |
any one or more 1859 1860 |
another 1861 1866 |
species, species, 1869 1872 | species 1859 1860 1861 1866 |
if we were to examine them
ever
so closely, unless we
....... 1869 1872 | likewise 1859 1860 1861 1866 |
possessed
most most 1869 1872 | many 1859 1860 1861 1866 |
of the intermediate
links; links; 1869 1872 | links 1859 1860 1861 1866 |
and owing to the imperfection of the geological record, we have no just right to and owing to the imperfection of the geological record, we have no just right to 1869 1872 |
between their past or parent and present states; and these many links we could hardly ever 1859 1860 |
between their past and present states; and these many links we could hardly ever 1861 1866 |
expect to
find so many links. find so many links. 1869 1872 |
discover, owing to the imperfection of the geological record. 1859 1860 1861 1866 |
If two or three, or even more linking forms were discovered, they would simply be ranked as
so many new species, more especially if found in different geological sub-stages, let their differences be ever so slight. Numerous existing doubtful forms could be named which are probably varieties; but who will pretend that in future ages so many fossil links will be discovered, that naturalists will be able to decide,
whether or not whether or not 1869 1872 |
on the common view, whether or not 1859 1860 1861 |
whether or not on the common view 1866 |
these doubtful forms
ought to be called ought to be called 1869 1872 |
are 1859 1860 1861 1866 |
varieties? ↑1 blocks not present in 1861 1866 1869 1872; present in 1859 1860 | As long as most of the links between any two species are unknown, if any one link or intermediate variety be discovered, it will simply be classed as another and distinct species.
|
Only a small portion of the world has been
geologically geologically 1859 1860 1861 1869 1872 | geological 1866 |
explored. Only organic beings of certain classes can be preserved in a fossil condition, at least in any great number. Many species when once formed never undergo any further
change change 1869 1872 | change, 1866 |
but become extinct without leaving modified descendants; and the periods, during which species have undergone modification, though long as measured by years, have probably been short in comparison with the periods during which they have
retained the same form. Widely
ranging species vary
most, and varieties are often at first local,—
both causes rendering the discovery of intermediate links less
likely. Local varieties will not spread into other and distant regions until they are considerably modified and im-
proved;
and when they
have have 1869 1872 | do 1859 1860 1861 1866 |
spread,
and are and are 1869 1872 | if 1859 1860 1861 1866 |
discovered in a geological formation, they will
appear as if suddenly created there, and will be simply classed as new species. Most formations have been
intermittent in their accumulation; and their duration,
I am inclined to believe, has
been shorter than the average
|