| → of 1859 1860 1861 |
| not furnished with membrane, of the 1866 1869 |
| not furnished with membrane of the 1872 |
|
| → — yet the water-hen 1861 |
| yet the water-hen 1859 1860 |
| —the water-hen and landrail are members of this order, yet the first 1866 1869 |
| — the water-hen 1872 |
|
| → is 1859 1860 1861 1866 1869 |
| and landrail are members of this order, yet the first is 1872 |
|
| → petrels 1859 1860 1861 |
| diving Hymenoptera, and petrels 1866 1869 1872 |
|
|
On the other
grebes and coots are eminently aquatic, although their toes are only bordered by membrane. What seems plainer than that the long
→of
are formed for walking over swamps and floating
→— yet the water-hen
→is
nearly as aquatic as the
and the
nearly as terrestrial as the quail or partridge. In such cases, and many others could be given, habits have changed without a corresponding change of structure. The webbed feet of the upland goose may be said to have become
in function, though not in structure. In the frigate-bird, the
membrane between the toes shows that structure has begun to change. |
|
| He who believes in separate and innumerable acts of creation
say, that in these cases it has pleased the Creator to cause a being of one type to take the place of one
another type; but this seems to me only
the fact in dignified language. He who believes in the struggle for existence and in the principle of natural selection, will acknowledge that every organic being is constantly endeavouring to increase in numbers; and that if any one
ever so little, either in habits or structure, and thus
an advantage over some other inhabitant of the
it will seize on the place of that inhabitant, however different
may be from its own place. Hence it will cause him no surprise that there should be geese and frigate-birds with webbed feet,
living on the dry land
rarely alighting on the water; that there should be long-toed
living in meadows instead of in swamps; that there should be woodpeckers where
a tree grows; that there should be diving
and
→petrels
with the habits of auks. |
|
|
| To
|
