| → include few 1859 1860 1861 1866 |
| do not include many 1869 1872 |
|
| → by catastrophes; and 1859 1860 1861 1866 1869 |
| OMIT 1872 |
|
|
from one parent, and have migrated from some one
and when we better know the many means of migration, then, by the light which geology now throws, and will continue to throw, on former changes of climate and of the level of the land, we shall surely be enabled to trace in an admirable manner the former migrations of the inhabitants of the whole world. Even at present, by comparing the differences
the inhabitants of the sea on the opposite sides of a continent, and the nature of the various inhabitants
that continent in relation to their apparent means of immigration, some light can be thrown on ancient geography. |
|
| The noble science of Geology loses glory from the extreme imperfection of the record. The crust of the earth with its
remains must not be looked at as a well-filled museum, but as a poor collection made at hazard and at rare intervals. The accumulation of each great fossiliferous formation will be recognised as having depended on an unusual concurrence of
and the blank intervals between the successive stages as having been of vast duration. But we shall be able to gauge with some security the duration of these intervals by a comparison of the preceding and succeeding organic forms. We must be cautious in attempting to correlate as strictly contemporaneous two formations, which
→include few
identical species, by the general succession of
forms of life. As species are produced and exterminated by slowly acting and still existing causes, and not by miraculous acts of
and
→by catastrophes; and
as the most important of all causes of organic change is one which is almost independent of altered and perhaps suddenly altered physical conditions, namely, the mutual relation of organism to organism,— the improvement of one
entailing the improvement or the extermination of
|
