| → we cannot doubt that 1861 1866 |
| I have no doubt that 1859 1860 |
| OMIT 1869 1872 |
|
| → due to some quite distinct cause, probably 1859 1860 1861 1866 |
| probably in chief part due 1869 1872 |
|
| → the hooks 1859 1860 1861 1866 |
| and which there is reason to believe from the distribution of the thorn-bearing species in Africa and South America, serves as a defence against browsing quad- rupeds, so the hooks 1869 |
| and which, as there is reason to believe from the distribution of the thorn-bearing species in Africa and South America, serve as a defence against browsing quadrupeds, so the spikes 1872 |
|
| → have arisen from unknown laws of growth, and 1859 1860 1861 1866 |
| first 1869 |
| at first 1872 |
|
| → subsequently 1859 1860 1861 1866 |
| developed for this object, and subsequently been 1869 |
| developed for this object, and subsequently have been improved and 1872 |
|
| → undergoing 1859 1860 1861 1866 |
| as it underwent 1869 1872 |
|
| → producing slight and unimportant variations; 1859 1860 1861 1866 |
| of each slight variation or individual difference; 1869 1872 |
|
|
we did not know that there were many black and pied kinds, I dare say that we should have thought that the green colour was a beautiful adaptation to
this tree-frequenting bird from its enemies; and consequently that it was a character of
and
been acquired through natural selection; as it is,
→we cannot doubt that
the colour is
→due to some quite distinct cause, probably
to sexual selection. A trailing
in the Malay
climbs the loftiest trees by the aid of exquisitely constructed hooks clustered around the ends of the branches, and this contrivance, no doubt, is of the highest service to the plant; but as we see nearly similar hooks on many trees which are not climbers,
→the hooks
on the
may
→have arisen from unknown laws of growth, and
have been
→subsequently
taken advantage of by the
→undergoing
further modification and
a climber. The naked skin on the head of a vulture is generally
as a direct adaptation for wallowing in putridity; and so it may be, or it may possibly be due to the direct action of putrid matter; but we should be very cautious in drawing any such inference, when we see that the skin on the head of the clean-feeding male
is likewise naked. The sutures in the skulls of young mammals have been advanced as a beautiful adaptation for aiding parturition, and no doubt they facilitate, or may be indispensable for this act; but as sutures occur in the skulls of young birds and reptiles, which have only to escape from a broken egg, we may infer that this structure has arisen from the laws of growth, and has been taken advantage of in the parturition of the higher animals. |
|
| We are profoundly ignorant of the
→producing slight and unimportant variations;
and we are
made conscious of this by reflecting on
|
