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See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1866
1869
1872

→ it would be difficult to prove it. 1859 1860 1861 1866 1869
difficult of proof. 1872
→ it, if we compare 1859 1860 1861 1866
the same rule in 1869 1872
→ fresh-water productions, in which so many genera 1859 1860 1861 1866
of the inhabitants of fresh water, for many of the genera in the most distinct classes 1869 1872
→ in world-ranging genera all 1860 1861
in world- ranging genera all 1859
all 1866
all, but that some of 1869 1872
→ have a wide range, or even that they have on an average a wide range; but only that some of the species 1859 1860 1861
in world-ranging genera, but that some of them, 1866
in the genera which range very widely, have themselves very wide ranges. 1869
have very wide ranges in the genera which 1872
→ For instance, two varieties of the same species inhabit America and Europe, and 1859 1860 1861
Nor is it meant that 1866 1869 1872
→ thus has an immense range; but, if the variation had been a little greater, the 1859 1860 1861
have on an average a very wide range; for this will largely depend on how far the process of modification has gone; for instance, 1866
in such genera have on an average a very wide range; for this will largely depend on how far the process of modification has gone; for instance, 1869 1872
→ would have been ranked as distinct species, 1859 1860 1861
of the same species inhabit America and Europe, 1866
of the same species inhabit America and Europe, and thus the species has an immense range; but, if variation were to be carried a little further, the two varieties would be ranked as distinct species, 1869 1872
→ the common range 1859 1860 1861
the species thus has an immense range; but, if the variation had been carried a little further, the two varieties 1866
the range 1869
their range 1872
→ greatly 1859 1860 1861 1869 1872
ranked as distinct species, and the range would have been greatly 1866
→ a genus having descended from a single parent, though now 1859 1860 1861 1866
the same genus, though now 1869
a genus, though 1872
→ we 1859 1860 1861 1866
are descended from a single progenitor, we 1869 1872
many of the species have very wide ranges. I can hardly doubt that this rule is generally true, though →it would be difficult to prove it. Amongst mammals, we see it strikingly displayed in Bats, and in a lesser degree in the Felidæ and Canidæ. We see →it, if we compare the distribution of butterflies and beetles. So it is with most →fresh-water productions, in which so many genera range over the world, and many
of the
individual
species have enormous ranges. It is not meant that →in world-ranging genera all the species → have a wide range, or even that they have on an average a wide range; but only that some of the species
range
range
very
very
widely.
widely;
widely;
for
for
for
the
the
the
facility
facility
facility
with
with
with
which
which
which
widely-ranging
widely-ranging
widely-ranging
species
species
species
vary
vary
vary
and
and
and
give
give
give
rise
rise
rise
to
to
to
new
new
new
forms
forms
forms
will
will
will
largely
largely
largely
determine
determine
determine
their
their
their
average
average
average
range.
range.
range.
→For instance, two varieties of the same species inhabit America and Europe, and the species →thus has an immense range; but, if the variation had been a little greater, the two varieties →would have been ranked as distinct species, and →the common range would
be
have been
→greatly reduced. Still less is it meant, that
a
a
species which
have
apparently has
the capacity of crossing barriers and ranging
widely
widely,
as in the case of certain powerfully-winged birds, will necessarily range widely; for we should never forget that to range widely implies not only the power of crossing barriers, but the more important power of being victorious in distant lands in the struggle for life with foreign associates. But
according to
on
the view
that
of
all the species of →a genus having descended from a single parent, though now distributed
at
to
the most remote points of the world, →we ought to find, and I believe as a general rule we do find, that some at least of the species range very
widely.
widely;
for
for
it
it
is
is
necessary
necessary
that
that
the
the
unmodified
unmodified
parent
parent
should
should
have ranged
range
range
widely,
widely,
undergoing
undergoing
modification
modification
during
during
its
its
diffusion,
diffusion,
and
and
should
should
have placed
place
place
itself
itself
under
under
diverse
diverse
conditions
conditions
favourable
favourable