On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeD. Appleton, 1870 - 440 стор. |
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Сторінка 7
... offspring not uni versal - Hybrids and mongrels compared independently of their fertility - Sum . mary , 217 CHAPTER IX . ON THE IMPERFECTION OF THE GEOLOGICAL RECORD . On the absence of intermediate varieties at the present day - On ...
... offspring not uni versal - Hybrids and mongrels compared independently of their fertility - Sum . mary , 217 CHAPTER IX . ON THE IMPERFECTION OF THE GEOLOGICAL RECORD . On the absence of intermediate varieties at the present day - On ...
Сторінка 16
... offspring not perfectly like their parents or variable . Sterility has been said to be the bane of horticulture but on this view we owe variability to the same cause which produces sterility ; and variability is the source of all the ...
... offspring not perfectly like their parents or variable . Sterility has been said to be the bane of horticulture but on this view we owe variability to the same cause which produces sterility ; and variability is the source of all the ...
Сторінка 19
... offspring at a correspond- ing age , though sometimes earlier . In many cases this could not be otherwise : thus the inherited peculiarities in . the horns of cattle could appear only in the ОНАР . І .; 19 UNDER DOMESTICATION .
... offspring at a correspond- ing age , though sometimes earlier . In many cases this could not be otherwise : thus the inherited peculiarities in . the horns of cattle could appear only in the ОНАР . І .; 19 UNDER DOMESTICATION .
Сторінка 20
... offspring when nearly mature ; peculiarities in the silkworm are known to appear at the corresponding caterpillar or cocoon stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and ...
... offspring when nearly mature ; peculiarities in the silkworm are known to appear at the corresponding caterpillar or cocoon stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and ...
Сторінка 22
... offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many very closely allied natural species - for instance , of the many foxes - inhabiting different quarters of ...
... offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many very closely allied natural species - for instance , of the many foxes - inhabiting different quarters of ...
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On the Origin of Species by Means of Natural Selection: Or The ..., Том 2 Charles Darwin Повний перегляд - 1888 |
Загальні терміни та фрази
accumulated adapted affinities allied species America amount analogous ancient animals appear become bees believe birds breeds cause cells chapter characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species disuse divergence domestic doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ laws less living look male mammals manner migration modification modified descendants natural selection naturalists nearly nest occasional offspring organic organisation perfect pigeons pistil plants pollen present probably produced progenitor ranked reciprocal crosses remarked resemble rudimentary seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion variability variation vary whole widely
Популярні уривки
Сторінка 423 - It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other and dependent upon each other in so complex a manner, have all been produced by laws acting around us.
Сторінка 422 - In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
Сторінка 423 - Variability from the indirect and direct action of the conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of higher animals, directly follows.
Сторінка 9 - On my return home, it occurred to me, in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years' work I allowed myself to speculate on the subject, and drew up some short notes ; these I enlarged in 1844 into a sketch of the conclusions which then seemed to me probable : from that period to the present day I have steadily pursued the same object. I hope that I may...
Сторінка 423 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.
Сторінка 61 - I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection, in order to mark its relation to man's power of selection.
Сторінка 72 - Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice.
Сторінка 169 - If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
Сторінка 420 - Our classifications will come to be, as far as they can be so made, genealogies ; and will then truly give what may be called the plan of creation.
Сторінка 11 - ... species had not been independently created, but had descended, like varieties, from other species. Nevertheless, such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which most justly excites our admiration.