| → on the whole, higher 1861 1866 |
| in some vague sense, higher 1859 1860 |
| on the whole, higher in the scale of organisation 1869 1872 |
|
| → are 1859 1860 1861 1866 |
| must be higher, 1869 1872 |
|
| → higher in so far 1866 |
| in so far higher 1859 1860 1861 |
| in so far 1869 1872 |
|
| → life; they will also generally have had their organs more specialised for different functions. 1861 1866 |
| life. 1859 1860 |
| life; they have also generally had their organs more specialized for different functions. 1869 |
| life; they have also generally had their organs more specialised for different functions. 1872 |
|
| → little improved organisation 1861 1866 |
| but little improved structures, 1869 1872 |
|
| → though becoming under each grade 1861 1866 |
| by having become at each stage 1869 1872 |
|
| → within a confined 1859 1860 1861 1866 |
| generally within the same 1869 |
| within the same 1872 |
|
|
existing
groups. Recent forms are generally looked
as being,
→on the whole, higher
than ancient
forms; and they
→are
→higher in so far
as the later and more improved forms have conquered the older and less improved
in the struggle for
→life; they will also generally have had their organs more specialised for different functions. This fact is perfectly compatible with numerous beings still retaining
simple and
→little improved organisation
fitted for simple conditions of life; it is likewise compatible with some forms having retrograded in organisation,
→though becoming under each grade
of descent better fitted for
and degraded habits of life. Lastly, the
of the long endurance of allied forms on the same continent,— of marsupials in Australia, of edentata in America, and other such cases,— is intelligible, for
→within a confined
the
and the extinct will
be
by descent. |
|
| Looking to geographical distribution, if we admit that there has been during the long course of ages much migration from one part of the world to another, owing to former climatal and geographical changes and to the many occasional and unknown means of dispersal, then we can understand, on the theory of descent with modification, most of the great leading facts in Distribution. We can see why there should be so striking a parallelism in the distribution of organic beings throughout space, and in their geological succession throughout time; for in both cases the beings have been connected by the bond of ordinary generation, and the means of modification have been the same. We see the full meaning of the wonderful fact, which
struck every traveller, namely, that on the same continent, under the most diverse conditions, under heat and cold, on mountain and lowland, on deserts and marshes, most
|
