Natural Selection and Tropical Nature: Essays on Descriptive and Theoretical BiologyMacmillan and Company, 1891 - 492 pages |
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Page 4
... individual operation . The great increase of our knowledge within the last twenty years , both of the present and past history of the organic world , has accumulated a body of facts which should afford a sufficient foundation for a ...
... individual operation . The great increase of our knowledge within the last twenty years , both of the present and past history of the organic world , has accumulated a body of facts which should afford a sufficient foundation for a ...
Page 14
... individuals and also as to variety of species and generic group , just as we now find that the places best adapted to the rapid growth and increase of individuals also contain the greatest profusion of species and the greatest variety ...
... individuals and also as to variety of species and generic group , just as we now find that the places best adapted to the rapid growth and increase of individuals also contain the greatest profusion of species and the greatest variety ...
Page 20
... individuals removed by these checks must be on the whole inferior to those that survived . In the two hours that elapsed before my ague fit was over I had thought out almost the whole of the theory , and the same evening I sketched the ...
... individuals removed by these checks must be on the whole inferior to those that survived . In the two hours that elapsed before my ague fit was over I had thought out almost the whole of the theory , and the same evening I sketched the ...
Page 23
... individuals and of entire species . These conditions will also determine the population of a species ; and by a careful consideration of all the circumstances we may be enabled to comprehend , and in some degree to explain , what at ...
... individuals and of entire species . These conditions will also determine the population of a species ; and by a careful consideration of all the circumstances we may be enabled to comprehend , and in some degree to explain , what at ...
Page 24
... individuals existing in any given country , twice that number must perish annually , -a striking result , but one which seems at least highly probable , and is perhaps under rather than over the truth . It would therefore appear that ...
... individuals existing in any given country , twice that number must perish annually , -a striking result , but one which seems at least highly probable , and is perhaps under rather than over the truth . It would therefore appear that ...
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Common terms and phrases
abundant adapted allied species America animals ants appear attract bamboo Batavia beautiful become bees beetles birds branches brilliant butterflies caterpillars causes chaffinches character civilised climate colour Colours of Animals concealment conspicuous curious Darwin distinct earth equatorial zone evidence exactly existence extinct facts families favourable feet fertilised flowers foliage forests genera genus geological gravel green groups habits Heliconidæ humming-birds imitation important increase inhabit insects instinct islands kind larvæ laws less Malay Malay Archipelago male mammalia mimicry mode modified moths natural selection naturalists nectary nest never observed occur organic organisation origin Origin of Species Papilio peculiar phenomena pigeons plants Pliocene plumage probably produced protection race remarkable render resemble savage sexes sexual selection sometimes South South America spots structure sun-birds surface tail temperate theory tints tion trees tropical variations varied variety vegetation whole wings yellow
Popular passages
Page 205 - ... be said to be the result of the molecular forces of the protoplasm which displays it. And if so, it must be true, in the same sense and to the same extent, that the thoughts to which I am now giving utterance, and your thoughts regarding them, are the expression of molecular changes in that matter of life which is the source of our other vital phenomena.
Page 210 - WILL, while we have no knowledge of any other primary cause of force, it does not seem an improbable conclusion that all force may be will-force ; and thus, that the whole universe, is not \ merely dependent on, but actually is, the WILL of higher intelligences or of one Supreme Intelligence.
Page 26 - It seems evident that what takes place among the individuals of a species must also occur among the several allied species of a group, — viz., that those which are best adapted to obtain a regular supply of food, and to defend themselves against the attacks of their enemies and the vicissitudes of the seasons, must necessarily obtain and preserve a superiority in population; while those species which from some defect of power or organization are the least capable of counteracting the vicissitudes...
Page 32 - Even the peculiar colours of many animals, especially insects, so closely resembling the soil or the leaves or the trunks on which they habitually reside, are explained on the same principle; for though in the course of ages varieties of many tints may have occurred, yet those races having colours best adapted to concealment from their enemies would inevitably survive the longest.
Page 217 - Observations Made at the Magnetical and Meteorological Observatory at Batavia. Published by order of the Government of Netherlands India. Vol. I. Meteorological, from Jan. 1866 to Dec. 1868 ; and Magnetical, from July 1867 to June 1870. By Dr. PA Bergsma. Batavia, 1871.
Page 33 - ... to follow. An origin such as is here advocated will also agree with the peculiar character of the modifications of form and structure which obtain in organized beings — the many lines of divergence from a central type, the increasing efficiency and power of a particular organ through a succession of allied species, and the remarkable persistence of unimportant parts such as colour, texture of plumage and hair, form of horns or crests, through a series of species differing considerably in more...
Page 204 - ... to the other. They appear together, but we do not know why. Were our minds and senses so expanded, strengthened, and illuminated as to enable us to see and feel the very molecules of the brain ; were we capable of following all their motions, all their groupings, all their electric discharges, if such there be ; and were we intimately acquainted with the corresponding states of thought and feeling, we should be as far as ever from the solution of the problem, " How are these physical processes...
Page 154 - Strictly speaking, therefore, Mr. Darwin's theory is not a theory on the Origin of Species at all, but only a theory on the causes which lead to the relative success or failure of such new forms as may be born into the world.
Page 18 - Every species has come into existence coincident both in time and space with a preexisting closely allied species," Connects together and renders intelligible a vast number of independent and hitherto unexplained facts.
Page 275 - As the laws of Nature must be the same for all beings, the conclusions furnished by this group of insects must be applicable to the whole organic world; therefore, the study of butterflies — creatures selected as the types of airiness and frivolity — instead of being despised, will some day be valued as one of the most important branches of Biological science.