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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 84 of 119 (4/p)
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Export to Excel select * from OriginOfSpecies order by ordinal desc limit 332, 4 (Page 84: Row)
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02 - Variations Under Nature 02-06 - Many of the Species included within the Larger Genera resemble Varieties in being very closely, but unequally, related to each other, and in having restricted ranges 20 And what are varieties but groups of forms, unequally related to each other, and clustered round certain forms- that is, round their parent-species. Undoubtedly there is one most important point of difference between varieties and species; namely, that the amount of difference between varieties, when compared with each other or with their parent-species, is much less than that between the species of the same genus.

But when we come to discuss the principle, as I call it, of Divergence of Character, we shall see how this may be explained, and how the lesser differences between varieties tend to increase into the greater differences between species.

There is one other point which is worth notice.

Varieties generally have much restricted ranges: this statement is indeed scarcely more than a truism, for, if a variety were found to have a wider range than that of its supposed parent-species, their denominations would be reversed.

But there is reason to believe that the species which are very closely allied to other species, and in so far resemble varieties, often have much restricted ranges.

For instance, Mr. H. C. Watson has marked for me in the well-sifted London Catalogue of Plants (4th edition) 63 plants which are therein ranked as species, but which he considers as so closely allied to other species as to be of doubtful value: these 63 reputed species range on an average over 6.9 of the provinces into which Mr. Watson has divided Great Britain. Now, in this same Catalogue, 53 acknowledged varieties are recorded, and these range over 7.7 provinces; whereas, the species to which these varieties belong range over 14.3 provinces.

Hewett Cottrell Watson
Hewett Cottrell Watson


So that the acknowledged varieties have nearly the same
restricted average range, as have the closely allied forms, marked for me by Mr. Watson as doubtful species, but which are almost universally ranked by British botanists as good and true species.
03 - Struggle for Existence 03-10 - Struggle for Life most severe between Individuals and Varieties of the same Species 20 How frequently we hear of one species of rat taking the place of another species under the most different climates!

In Russia the small Asiatic cockroach has everywhere driven before it its great congener.

rat
rat

Russia
Russia

cockroach
cockroach


In Australia the imported hive-bee is rapidly exterminating the small, stingless native bee. One species of charlock has been known to supplant another species; and so in other cases.

Australia
Australia

Hive Bee
Hive Bee

charlock
charlock


We can dimly see why the competition should be most severe between allied forms, which fill nearly the same place in the economy of nature; but probably in no one case could we precisely say why one species has been victorious over another in the great battle of life.
12 - Geographical Distribution -- continued 12-40 - On the relations of the inhabitants of islands to those of the nearest mainland 20 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.

England
England

europe
europe

Australia
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 on the lapse of time, and as during changes of level it is obvious that islands separated by shallow channels are more likely to have been continuously united within a recent period to the mainland than islands separated by deeper channels, we can understand the frequent relation between the depth of the sea and the degree of affinity of the mammalian inhabitants of islands with those of a neighbouring continent, an explicable relation on the view of independent acts of creation.
12 - Geographical Distribution -- continued 12-30 - Absence of Batrachians and of terrestrial Mammals 20 I have taken pains to verify this assertion, and I have found it strictly true.

I have, however, been assured that a frog exists on the mountains of the great island of New Zealand; but I suspect that this exception (if the information be correct) may be explained through glacial agency.

New Zealand
New Zealand


This general absence of frogs, toads, and newts on so many oceanic islands cannot be accounted for by their physical conditions; indeed it seems that islands are peculiarly well fitted for these animals; for frogs have been introduced into Madeira, the Azores, and Mauritius, and have multiplied so as to become a nuisance.

island
island

Madeira
Madeira

Azores
Azores

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Mauritius