| Comparison with 1861 |
|
through natural selection
in their new homes in relation to their new position, and we can understand the presence of endemic bats on islands,
with the absence of all terrestrial
mammals. ↑| 1 blocks not present in 1859 1860 1861 1866; present in 1869 1872 | | Another interesting relation exists, namely between the depth of the sea separating islands from each other or from the nearest continents,
and the degree of affinity of their mammalian inhabitants.
|
|
| Besides the absence of terrestrial mammals in relation to the remoteness of islands from continents, there is also a relation,
to a certain extent independent of distance, between the depth of the sea separating an island from the neighbouring mainland, and the presence
in both of the same mammiferous species or of allied species in a more or less modified condition. Mr. Windsor Earl has made some striking observations on this head
in
regard to the great Malay Archipelago, which is traversed near Celebes by a space of deep ocean;
and this space
separates two widely distinct mammalian faunas. On either side the islands are situated on moderately deep
submarine banks,
and they
are inhabited by closely allied or identical
quadrupeds. No doubt some few anomalies occur in this great archipelago, and there is much difficulty in forming a judgment in some cases owing to the probable naturalisation of certain mammals through man's agency; but we shall soon have much light thrown on the natural history of this archipelago by the admirable zeal and researches of Mr. Wallace. I have not as yet had time to follow up this subject in all other
quarters of the world; but as far as I have gone, the relation generally
holds good. We see Britain
separated by a shallow channel from Europe, and the mammals are the same on both sides; we meet with analogous facts on many islands separated by similar channels from
Australia. The West Indian Islands
stand on
a deeply submerged bank, nearly 1000 fathoms in depth, and here we find American forms, but the species and even the genera are distinct. As the amount of modification in all cases depends to a certain degree
|
through natural selection | through natural selection 1859 1860 1861 1866 |
| OMIT 1869 1872 |
| islands, 1859 1860 1861 1866 | | oceanic islands, 1869 1872 |
| terrestrial 1859 1860 1861 1866 | | other terrestrial 1869 1872 |
| 1 blocks not present in 1859 1860 1861 1866; present in 1869 1872 | | Another interesting relation exists, namely between the depth of the sea separating islands from each other or from the nearest continents,
and the degree of affinity of their mammalian inhabitants.
|
|
Besides the absence of terrestrial mammals in relation to the remoteness of islands from continents, there is also a
relation, | relation, 1859 1860 1861 | | relation 1866 |
| presence 1859 1860 1861 | | pre- sence 1866 |
| head 1859 1860 1861 | | head, 1866 1869 1872 |
| in 1859 1860 1861 |
| since fully confirmed by Mr. Wallace's admirable researches, in 1866 |
| since greatly extended by Mr. Wallace's admirable researches, in 1869 1872 |
| ocean; 1859 1860 1861 1866 | | ocean, 1869 1872 |
| space 1859 1860 1861 1866 | space 1869 1872 |
| are situated on moderately deep 1859 1860 1861 1866 |
| stand on a moderately shallow 1869 1872 |
| banks, 1859 1860 1861 1866 | | bank, 1869 1872 |
| they 1859 1860 1861 1866 | | these 1869 | | these islands 1872 |
| closely allied or identical 1859 1860 1861 1866 |
| the same or by very closely allied 1869 |
| the same or by closely allied 1872 |
| other 1859 1860 1861 1866 | other 1869 1872 |
| generally 1859 1860 1861 1866 1869 | generally 1872 |
| We see Britain 1859 1860 1861 1866 |
| For instance, Britain is 1869 1872 |
| we meet with analogous facts on many islands separated by similar channels from 1859 1860 1861 1866 |
| and so it is with all the islands near the shores of 1869 1872 |
| Islands 1859 1860 1861 1866 | | Islands, 1869 1872 |
| stand on 1859 1860 1861 1866 |
| on the other hand, stand on 1869 1872 |
| distinct. 1859 1860 1861 1866 | | quite distinct. 1869 1872 |
| in all cases depends to a certain degree 1859 1860 1861 1866 |
| which animals of all kinds undergo, partly depends 1869 1872 |
|
