Contributions to the Theory of Natural Selection: A Series of EssaysMacmillan and Company, 1871 - 384 pages |
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Page 23
... similar class of facts has been long re- cognised . Abortive stamens , rudimentary floral en- velopes and undeveloped carpels , are of the most frequent occurrence . To every thoughtful naturalist the question must arise , What are ...
... similar class of facts has been long re- cognised . Abortive stamens , rudimentary floral en- velopes and undeveloped carpels , are of the most frequent occurrence . To every thoughtful naturalist the question must arise , What are ...
Page 36
... similar unfavourable conditions might also become extinct . The superior variety would then alone remain , and on a return to favourable circumstances would rapidly increase in numbers and occupy the place of the extinct species and ...
... similar unfavourable conditions might also become extinct . The superior variety would then alone remain , and on a return to favourable circumstances would rapidly increase in numbers and occupy the place of the extinct species and ...
Page 41
... similar results must be produced by the action of principles constantly at work in nature . The powerful retractile talons of the falcon- and the cat - tribes have not been produced or increased by the volition of those animals ; but ...
... similar results must be produced by the action of principles constantly at work in nature . The powerful retractile talons of the falcon- and the cat - tribes have not been produced or increased by the volition of those animals ; but ...
Page 46
... similar princi- ples , and for a good many years it was decidedly in the ascendent . With such a favourable introduc- tion , and with such talented exponents , it must have become established if it had had any germ of truth in it ; yet ...
... similar princi- ples , and for a good many years it was decidedly in the ascendent . With such a favourable introduc- tion , and with such talented exponents , it must have become established if it had had any germ of truth in it ; yet ...
Page 54
... similar examples . The most arboreal lizards , the iguanas , are as green as the leaves they feed upon , and the slender whip - snakes are ren- dered almost invisible as they glide among the foliage by a similar colouration . How ...
... similar examples . The most arboreal lizards , the iguanas , are as green as the leaves they feed upon , and the slender whip - snakes are ren- dered almost invisible as they glide among the foliage by a similar colouration . How ...
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Contributions to the Theory of Natural Selection: A Series of Essays ... Alfred Russel Wallace No preview available - 2018 |
Contributions to the Theory of Natural Selection: A Series of Essays Alfred Russel Wallace No preview available - 2016 |
Common terms and phrases
abundant adapted affinity alike Amboyna anal valves animals antennæ appear Bates beautiful become bees beetles birds Borneo brilliant build butterflies caterpillars causes Celebes character closely allied species common concealed curious Danaidæ Darwin distinct eggs enemies equally exactly example existence extinct facts faculties favourable female birds flowers genera genus geological groups Guinea habits Heliconidæ imitation India individuals inhabiting insects instinct islands Java larvæ Lepidoptera less Longicorn Malayan male Mimeta mimic mimicry mode modifications Moluccas moths natural selection nectary nest never nidification number of species observations occur organic Origin of Species Ormenus Pammon Papilio Papilio Ulysses Papilionidæ peculiar phenomena plumage Polydorus possess probably produced protection race regions remarkable render resemble savage sexes sexual sexual selection shown spots structure Sumatra tail theory of natural Theseus tints tion trees tropical Tropidorhynchus variation varied varieties whole wings yellow young birds
Popular passages
Page 351 - ... the passage from the current to the needle, if not demonstrable, is thinkable, and that we entertain no doubt as to the final mechanical solution of the problem. But the passage from the physics of the brain to the corresponding facts of consciousness is unthinkable. Granted that a definite thought, and a definite molecular action in the brain occur simultaneously ; we do not possess the intellectual organ, nor apparently any rudiment of the organ, which would enable us to pass, by a process...
Page 358 - If, therefore, we have traced one force, however minute, to an origin in our own 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 28 - ... applied to high numbers, the results come nearer to what theory demands, and, as we approach to an infinity of examples, become strictly accurate. Now the scale on which nature works is so vast — the numbers of individuals and periods of time with which she deals approach so near to infinity, that any cause, however slight, and however liable to be veiled and counteracted by accidental circumstances, must in the end produce its full legitimate results.
Page 351 - ... 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 connected...
Page 349 - A superior intelligence has guided the development of man in a definite direction and for a special purpose, just as man guides the development of many animal and vegetable forms...
Page 358 - God of the Granite and the Rose ! Soul of the Sparrow and the Bee ! The mighty tide of Being flows Through countless channels, Lord, from Thee. It leaps to life in grass and flowers, Through every grade of being runs, While from Creation's radiant towers Its glory flames in Stars and Suns.
Page 31 - The powerful retractile talons of the falcon- and the cat-tribes have not been produced or increased by the volition of those animals; but among the different varieties which occurred in the earlier and less highly organized forms of these groups, those always survived longest which had the greatest facilities for seizing their prey.
Page 16 - One of the strongest arguments which have been adduced to prove the original and permanent distinctness of species is, that varieties produced in a state of domesticity are more or less unstable, and often have a tendency, if left to themselves, to return to the normal form of the parent species; and this instability is considered to be a distinctive peculiarity of all varieties, even of those occurring among wild animals in a state of nature, and to constitute a provision for preserving unchanged...
Page 24 - ... species will present various degrees of capacity for ensuring the means of preserving life; and it is thus we account for the abundance or rarity of species. Our ignorance will generally prevent us from accurately tracing the effects to their causes; but could we become perfectly acquainted with the organization and habits of the various species of animals, and could we measure the capacity of each for performing the different acts necessary to its safety and existence under all the varying circumstances...
Page 346 - Natural Selection could only have endowed the savage with a brain a little superior to that of an ape, whereas he actually possesses one but very little inferior to that of the average members of our learned societies.