Darwinism: An Exposition of the Theory of Natural Selection, with Some of Its Applications, Volumes 1-2Macmillan, 1889 - 494 páginas |
No interior do livro
Resultados 1-5 de 95
Página vi
... variation in domesticated animals and cultivated plants . I have endeavoured to secure a firm foundation for the theory in the variations of organisms in a state of nature ; and as the exact amount and precise character of these variations ...
... variation in domesticated animals and cultivated plants . I have endeavoured to secure a firm foundation for the theory in the variations of organisms in a state of nature ; and as the exact amount and precise character of these variations ...
Página vii
... variation , I commence with the Struggle for Existence , which is really the fundamental phenomenon on which natural selection depends , while the particular facts which illustrate it are comparatively familiar and very interesting . It ...
... variation , I commence with the Struggle for Existence , which is really the fundamental phenomenon on which natural selection depends , while the particular facts which illustrate it are comparatively familiar and very interesting . It ...
Página ix
... IN A STATE OF NATURE Importance of variability - Popular ideas regarding it - Variability of the lower animals - The variability of insects - Variation among lizards— Variation among birds - Diagrams of bird - variation -
... IN A STATE OF NATURE Importance of variability - Popular ideas regarding it - Variability of the lower animals - The variability of insects - Variation among lizards— Variation among birds - Diagrams of bird - variation -
Página x
... variation - Number of varying individuals - Variation in the mammalia - Variation in internal organs - Variations in the skull - Variations in the habits of animals - The variability of plants - Species which vary little - Con- cluding ...
... variation - Number of varying individuals - Variation in the mammalia - Variation in internal organs - Variations in the skull - Variations in the habits of animals - The variability of plants - Species which vary little - Con- cluding ...
Página xiv
... VARIATION AND HEREDITY Fundamental difficulties and objections - Mr . Herbert Spencer's factors of organic evolution - Disuse and effects of withdrawal of natural selection - Supposed effects of disuse among wild animals - Difficulty as ...
... VARIATION AND HEREDITY Fundamental difficulties and objections - Mr . Herbert Spencer's factors of organic evolution - Disuse and effects of withdrawal of natural selection - Supposed effects of disuse among wild animals - Difficulty as ...
Outras edições - Ver tudo
Darwinism: An Exposition of the Theory of Natural Selection, with Some of ... Alfred Russel Wallace Visualização integral - 1890 |
Darwinism: An Exposition of the Theory of Natural Selection, with Some of ... Alfred Russel Wallace Visualização integral - 1890 |
Darwinism: An Exposition of the Theory of Natural Selection, with Some of ... Alfred Russel Wallace Visualização integral - 1889 |
Palavras e frases frequentes
abundant adapted adduced allied species America amount animals and plants appears birds breed brilliant butterflies carnivora cause characters climate closely allied colours of animals common concealment conspicuous continued cross-fertilisation crossed curious Darwin dicotyledons distinct species domestic animals effects eggs enemies Eocene evidence extinct facts faculty favourable female fertile fertilisation flowers genera genus geological groups habits hybrids important increase individuals infertility inhabit insects intercrossing kind larvæ less living male mammalia mammals markings marsupials mimicry Miocene mode modified moths natural selection naturalists nests occur offspring organs Origin of Species peculiar pigeons Pliocene pollen portion possess probably produced Professor protectively coloured regions remarkable resemble seeds self-fertilisation Silurian similar specimens spots sterility structure struggle for existence supposed tail Tertiary theory tints tion toes trees tropical usually variability variation varied varieties vegetation warning colours whole wild wings Zealand
Passagens conhecidas
Página 40 - When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.
Página 132 - I did not formerly consider sufficiently the existence of structures, which, as far as we can at present judge, are neither beneficial nor injurious; and this I believe to be one of the greatest oversights as yet detected in my work.
Página 38 - Starting, and looking half round, I saw the lion just in the act of springing upon me. I was upon a little height ; he caught my shoulder as he sprang, and we both came to the ground below together. Growling horribly close to my ear, he shook me as a terrier dog does a rat.
Página 38 - Growling horribly, close to my ear, he shook me as a terrier dog does a rat. The shock produced a stupor similar to that which seems to be felt by a mouse after the first shake of the cat. It caused a sort of dreaminess, in which there was no sense of pain nor feeling of terror, though I was quite conscious of all that was happening.
Página 31 - Not far from Shelbyville, in the State of Kentucky, about five years ago, there was one of these breeding places, which stretched through the woods in nearly a north and south direction ; was several miles in breadth, and was said to be upwards of forty miles in extent ! In this tract, almost every tree was furnished with nests, wherever the branches could accommodate them.
Página 32 - I was astonished at their appearance. They were flying with great steadiness and rapidity, at a height beyond gunshot, in several strata deep, and so close together, that could shot have reached them, one discharge could not have failed of bringing down several individuals. From right to left as far as the eye could reach, the breadth of this vast procession extended ; seeming everywhere equally crowded.
Página 31 - The ground was strewed with broken limbs of trees, eggs, and young squab pigeons, which had been precipitated from above, and on which herds of hogs were fattening. Hawks, buzzards, and eagles, were sailing about in great numbers, and seizing the squabs from...
Página 19 - Paraguay, the parasitic insects would probably increase; and this would lessen the number of the navel-frequenting flies — then cattle and horses would become feral, and this would certainly greatly alter (as indeed I have observed in parts of South America) the vegetation: this again would largely affect the insects; and this, as we have just seen in Staffordshire, the insectivorous birds, and so onwards in ever-increasing circles of complexity.
Página 9 - Darwin that he is the Newton of natural history, and that, just so surely as that the discovery and demonstration by Newton of the law of gravitation established order in place of chaos and laid a sure foundation for all future study of the starry heavens, so surely has Darwin, by his discovery of the law of natural selection and his demonstration of the great principle of the preservation of useful variations in the struggle for life, not only thrown a flood of light on the process of development...