Natural Selection and Tropical Nature: Essays on Descriptive and Theoretical BiologyMacmillan and Company, 1891 - 492 pages |
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Page 11
... exactly analogous to those of geography . Closely allied species are found associated in the same beds , and the change from species to species appears to have been as gradual in time as in space . Geology , however , furnishes us with ...
... exactly analogous to those of geography . Closely allied species are found associated in the same beds , and the change from species to species appears to have been as gradual in time as in space . Geology , however , furnishes us with ...
Page 26
... Exactly the same laws will apply to mammals . Wild cats are prolific and have few enemies ; why then are they never as abundant as rabbits ? The only intelligible answer is , that their supply of food is more precarious . It appears ...
... Exactly the same laws will apply to mammals . Wild cats are prolific and have few enemies ; why then are they never as abundant as rabbits ? The only intelligible answer is , that their supply of food is more precarious . It appears ...
Page 32
... exactly like that of the centrifugal governor of the steam - engine , which checks and corrects any irregularities almost before they become evident ; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any ...
... exactly like that of the centrifugal governor of the steam - engine , which checks and corrects any irregularities almost before they become evident ; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any ...
Page 36
... Exactly the same thing has occurred with pigeons ; and in the case of rats and mice , the white variety has not been shown to be at all dependent on altera- tion of climate , food , or other external conditions . In many cases the wings ...
... Exactly the same thing has occurred with pigeons ; and in the case of rats and mice , the white variety has not been shown to be at all dependent on altera- tion of climate , food , or other external conditions . In many cases the wings ...
Page 38
... exactly harmonises with the lichen - coloured stones among which it delights to sit , that a person may walk through a flock of them without seeing a single bird ; while in winter its white plumage is an almost equal protection . The ...
... exactly harmonises with the lichen - coloured stones among which it delights to sit , that a person may walk through a flock of them without seeing a single bird ; while in winter its white plumage is an almost equal protection . The ...
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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.