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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 98 of 119 (4/p)
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Export to Excel select * from OriginOfSpecies order by ordinal limit 388, 4 (Page 98: Row)
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04 - Natural Selection 04-12 - On the Degree to which Organisation tends to advance 70 But to suppose that most of the many now existing low forms have not in the least advanced since the first dawn of life would be extremely rash; for every naturalist who has dissected some of the beings now ranked as very low in the scale, must have been struck with their really wondrous and beautiful organisation.

Nearly the same remarks are applicable if we look to the different grades of organisation within the same great group; for instance, in the vertebrata, to the co-existence of mammals and fish- amongst mammalia, to the coexistence of man and the Ornithorhynchus- amongst fishes, to the co-existence of the shark and the lancelet (Amphioxus), which latter fish in the extreme simplicity of its structure approaches the invertebrate classes.

Ornithorhynchus
Ornithorhynchus

shark
shark

lancelet
lancelet
05 - Laws of Variation 05-12 - Reversion to Long Lost Characters 70 I am aware that Colonel Hamilton Smith, who has written on this subject, believes that the several breeds of the horse are descended from several aboriginal species- one of which, the dun, was striped; and that the above described appearances are an due to ancient crosses with the dun stock.

Dun Horse
Dun Horse


But this view may be safely rejected; for it is highly improbable that the heavy Belgian cart-horse, Welsh ponies, Norwegian cobs, the lanky kattywar race, &c., inhabiting the most distant parts of the world, should all have been crossed with one supposed aboriginal stock.

Belgian Cart Horse
Belgian Cart Horse

Welsh Pony
Welsh Pony

Kathiwari Horse
Kathiwari Horse
04 - Natural Selection 04-13 - Convergence of Character 70 The process of extermination in such cases would be rapid, whereas the production of new species must always be slow.

Imagine the extreme case of as many species as individuals in England, and the first severe winter or very dry summer would exterminate thousands on thousands of species.

England
England


Rare species, and each species will become rare if the number of species in any country becomes indefinitely increased, will, on the principle often explained, present within a given period few favourable variations; consequently, the process of giving birth to new specific forms would thus be retarded.
05 - Laws of Variation 05-02 - Use and Disuse of Parts, combined with Natural Selection, Organs of Flight and Vision 70 It is difficult to imagine conditions of life more similar than deep limestone caverns under a nearly similar climate; so that, in accordance with the old view of the blind animals having been separately created for the American and European caverns, very close similarity in their organisation and affinities might have been expected.

This is certainly not the case if we look at the two whole faunas; and with respect to the insects alone, Schiodte has remarked, "We are accordingly prevented from considering the entire phenomenon in any other light than something purely local, and the similarity which is exhibited in a few forms between the Mammoth cave (in Kentucky) and the caves in Carniola, otherwise than as a very plain expression of that analogy which subsists generally between the fauna of Europe and of North America."

On my view we must suppose that American animals, having in most cases ordinary powers of vision, slowly migrated by successive generations from the outer world into the deeper and deeper recesses of the Kentucky caves, as did European animals into the caves of Europe.

We have some evidence of this gradation of habit; for, as Schiodte remarks, "We accordingly look upon the subterranean faunas as small ramifications which have penetrated into the earth from the geographically limited faunas of the adjacent tracts, and which, as they extended themselves into darkness, have been accommodated to surrounding circumstances.

Animals not far remote from ordinary forms, prepare the transition from light to darkness.

Next follow those that are constructed for twilight; and, last of all, those destined for total darkness, and whose formation is quite peculiar."

These remarks of Schiodte's it should be understood, apply not to the same, but to distinct species.

By the time that an animal had reached, after numberless generations, the deepest recesses, disuse will on this view have more or less perfectly obliterated its eyes, and natural selection will often have effected other changes, such as an increase in the length of the antennae or palpi, as a compensation for blindness.

Notwithstanding such modifications, we might expect still to see in the cave-animals of America, affinities to the other inhabitants of that continent, and in those of Europe to the inhabitants of the European continent.

And this is the case with some of the American cave-animals, as I hear from Professor Dana; and some, of the European cave insects are very closely allied to those of the surrounding country.

It would be difficult to give any rational explanation of the affinities of the blind cave-animals to the other inhabitants of the two continents on the ordinary view of their independent creation.

That several of the inhabitants of the caves of the Old and New Worlds should be closely related, we might expect from the well-known relationship of most of their other productions.

As a blind species of Bathyscia is found in abundance on shady rocks far from caves, the loss of vision in the cave-species of this one genus has probably had no relation to its dark habitation; for it is natural that an insect already deprived of vision should readily become adapted to dark caverns.

Another blind genus (Anophthaimus) offers this remarkable peculiarity, that the species, as Mr. Murray observes, have not as yet been found anywhere except in caves; yet those which inhabit the several eaves of Europe and America are distinct; but it is possible that the progenitors of these several species, whilst they were furnished with eyes, may formerly have ranged over both continents, and then have become extinct, excepting in their present secluded abodes.

anophthaimus
anophthaimus


Far from feeling surprise that some of the cave-animals should be very anomalous, as Agassiz has remarked in regard to the blind fish, the Amblyopsis, and as is the case with blind Proteus with reference to the reptiles of Europe, I am only surprised that more wrecks of ancient life have not been preserved, owing to the less severe competition to which the scanty inhabitants of these dark abodes will have been exposed.

amblyopsis
amblyopsis

proteus
proteus