indispensable for the preservation of all the transitional gradations between any two or more species. If such gradations were not
fully fully 1859 1860 | all fully 1861 1866 1869 1872 |
preserved, transitional varieties would merely appear as so many
distinct distinct 1859 1860 1861 1866 |
new and distinct 1869 |
new, though closely allied 1872 |
species. It
is, is, 1859 1860 | is 1861 1866 1869 1872 |
also, also, 1859 1860 | also 1861 1866 1869 1872 |
probable that each great period of subsidence would be interrupted by oscillations of level, and that slight climatal changes would intervene during such lengthy periods; and in these cases the inhabitants of the archipelago would
have to have to 1859 1860 | have to 1861 1866 1869 1872 |
migrate, and no closely consecutive record of their modifications could be preserved in any one formation. |
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Very many of the marine inhabitants of the archipelago now range thousands of miles beyond its confines; and analogy
leads me to leads me to 1859 1860 |
plainly leads to the 1861 1866 1869 1872 |
believe believe 1859 1860 | belief 1861 1866 1869 1872 |
that it would be chiefly these far-ranging
species species 1859 1860 1861 | species, 1866 1869 1872 |
which which 1859 1860 1861 |
though only some of them, which 1866 1869 1872 |
would oftenest produce new varieties; and the varieties would at first
generally generally 1859 1860 1861 1866 1869 | generally 1872 |
be local or confined to one place, but if possessed of any decided advantage, or when further modified and improved, they would slowly spread and supplant their parent-forms. When such varieties returned to their ancient homes, as they would differ from their former
state, state, 1859 1860 1861 1866 1869 | state 1872 |
in a nearly uniform, though perhaps extremely slight degree,
they they 1859 1860 |
and as they would be found embedded in slightly different sub-stages of the same formation, they 1861 1866 1869 1872 |
would, according to the principles followed by many palæontologists, be ranked as new and distinct species. |
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If
then, then, 1859 1860 | then 1861 1866 1869 1872 |
there be some degree of truth in these remarks, we have no right to expect to
find find 1859 1860 1861 | find, 1866 1869 1872 |
in our geological formations, an infinite number of those fine transitional
forms, forms, 1859 1860 | forms 1861 1866 1869 1872 |
which which 1859 1860 | which, 1861 1866 1869 1872 |
on
my my 1859 1860 1861 1866 | our 1869 1872 |
theory theory 1859 1860 | theory, 1861 1866 1869 1872 |
assuredly assuredly 1859 1860 | assuredly 1861 1866 1869 1872 |
have connected all the past and present species of the same group into one long and branching chain of life. We ought only to look for a few links,
some more closely, some more closely, 1859 1860 |
and such assuredly we do find— 1861 1866 1869 1872 |
some more
distantly distantly 1859 1860 | distantly, 1861 1866 1869 1872 |
related related 1859 1860 |
some more closely, related 1861 1866 1869 1872 |
to each other; and these links, let them be ever so close, if found in different stages of the same formation, would, by
most most 1859 1860 | many 1861 1866 1869 1872 |
palæonto- logists, palæonto- logists, 1859 | palæontologists, 1860 1861 1866 1869 1872 |
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