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OriginOfSpecies - 475 Rows
Column Type #Values Column Stats
id int(11) 475 Column Stats
subject varchar(80) 14 Column Stats
title varchar(250) 139 Column Stats
ordinal int(11) 30 Column Stats
description text 474 Column Stats

475 rows, page 113 of 119 (4/p)
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Export to Excel select * from OriginOfSpecies order by ordinal desc limit 448, 4 (Page 113: Row)
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12 - Geographical Distribution -- continued 12-30 - Absence of Batrachians and of terrestrial Mammals 10 With respect to the absence of whole orders on oceanic islands, Bory St. Vincent long ago remarked that Batrachians (frogs, toads, newts) have never been found on any of the many islands with which the great oceans are studded.

Bory Saint Vincent
Bory Saint Vincent

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frogs

toad
toad

newt
newt
12 - Geographical Distribution -- continued 12-40 - On the relations of the inhabitants of islands to those of the nearest mainland 10 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.

Malayan archipelago
Malayan archipelago

Celebes
Celebes


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.

Alfred Russel Wallace
Alfred Russel Wallace
12 - Geographical Distribution -- continued 12-50 - On colonisation from the nearest source with subsequent modification 10 The most striking and important fact for us in regard to the inhabitants of islands, is their affinity to those of the nearest mainland, without being actually the same species.

Numerous instances could be given of this fact.

I will give only one, that of the Galapagos Archipelago, situated under the equator, between 500 and 600 miles from the shores of South America.

Galapagos Islands
Galapagos Islands

South America
South America


Here almost every product of the land and water bears the unmistakeable stamp of the American continent.

There are twenty-six land birds, and twenty-five of those are ranked by Mr Gould as distinct species, supposed to have been created here; yet the close affinity of most of these birds to American species in every character, in their habits, gestures, and tones of voice, was manifest.

Augustus Addison Gould
Augustus Addison Gould


So it is with the other animals, and with nearly all the plants, as shown by Dr. Hooker in his admirable memoir on the Flora of this archipelago.

Joseph Dalton Hooker
Joseph Dalton Hooker
12 - Geographical Distribution -- continued 12-60 - Summary of the last and present chapters 10 In these chapters I have endeavoured to show, that if we make due allowance for our ignorance of the full effects of all the changes of climate and of the level of the land, which have certainly occurred within the recent period, and of other similar changes which may have occurred within the same period; if we remember how profoundly ignorant we are with respect to the many and curious means of occasional transport, a subject which has hardly ever been properly experimentised on; if we bear in mind how often a species may have ranged continuously over a wide area, and then have become extinct in the intermediate tracts, I think the difficulties in believing that all the individuals of the same species, wherever located, have descended from the same parents, are not insuperable.

And we are led to this conclusion, which has been arrived at by many naturalists under the designation of single centres of creation, by some general considerations, more especially from the importance of barriers and from the analogical distribution of sub-genera, genera, and families.

With respect to the distinct species of the same genus, which on my theory must have spread from one parent-source; if we make the same allowances as before for our ignorance, and remember that some forms of life change most slowly, enormous periods of time being thus granted for their migration, I do not think that the difficulties are insuperable; though they often are in this case, and in that of the individuals of the same species, extremely grave.

As exemplifying the effects of climatal changes on distribution, I have attempted to show how important has been the influence of the modern Glacial period, which I am fully convinced simultaneously affected the whole world, or at least great meridional belts.

As showing how diversified are the means of occasional transport, I have discussed at some little length the means of dispersal of fresh-water productions.

If the difficulties be not insuperable in admitting that in the long course of time the individuals of the same species, and likewise of allied species, have proceeded from some one source; then I think all the grand leading facts of geographical distribution are explicable on the theory of migration (generally of the more dominant forms of life), together with subsequent modification and the multiplication of new forms.

We can thus understand the high importance of barriers, whether of land or water, which separate our several zoological and botanical provinces.
island
island