See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1866
1869
1872

parent form of 1860 1861 1866
parent-form 1859

Let us now take a 1859 1860 1861 1866
It may be worth while to give another and 1869

case. 1859 1860 1861 1866
illustration of the action of natural selection. 1869

1 blocks not present in 1859 1860 1861 1866 1869; present in 1872
It may be worth while to give another and more complex illustration of the action of natural selection.

by 1859 1860 1861 1866
for instance, by 1869 1872

insects. 1859 1860 1861 1866
insects; but their visits do not in any way benefit the plant. 1869 1872

Let us now suppose a little sweet 1859 1860 1861 1866
Now, let us suppose that the 1869 1872

be born with an innate tendency to pursue certain kinds of prey. Nor can this be thought very improbable; for we often observe great differences in the natural tendencies of our domestic animals; one cat, for instance, taking to catch rats, another mice; one cat, according to Mr. St. John, bringing home winged game, another hares or rabbits, and another hunting on marshy ground and almost nightly catching woodcocks or snipes. The tendency to catch rats rather than mice is known to be inherited. Now, if any slight innate change of habit or of structure benefited an individual wolf, it would have the best chance of surviving and of leaving offspring. Some of its young would probably inherit the same habits or structure, and by the repetition of this process, a new variety might be formed which would either
supplant,
supplant
or coexist
with,
with
the parent form of
of
....
wolf. Or, again, the wolves inhabiting a mountainous district, and those frequenting the lowlands, would naturally be forced to hunt different prey; and from the continued preservation of the individuals best fitted for the two sites, two varieties
might
would
slowly be formed. These varieties would cross and blend where they met; but to this subject of intercrossing we shall soon have to return. I may add, that, according to Mr. Pierce, there are two varieties of the wolf inhabiting the Catskill Mountains in the United States, one with a light greyhound-like form, which pursues deer, and the other more bulky, with shorter legs, which more frequently attacks the
shepher's
shepherd's
flocks.
Let us now take a more complex case. Certain plants excrete
a
a
sweet juice, apparently for the sake of
elimi- nating
eliminating
something injurious
from,
from
the
their
sap: this is
effected,
effected
by glands at the base of the stipules in some Leguminosæ, and at the
backs
back
of the
leaves
leaf
of the common laurel. This juice, though small in quantity, is greedily sought by insects. Let us now suppose a little sweet