On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle of LifeAppleton, 1864 - 440페이지 |
도서 본문에서
81개의 결과 중 1 - 5개
v 페이지
... hand , that species undergo modification , and that the existing forms of life have descended by true gen- eration from pre - existing forms . Passing over authors of the classical period , and likewise Demaillet and Buffon , with whose ...
... hand , that species undergo modification , and that the existing forms of life have descended by true gen- eration from pre - existing forms . Passing over authors of the classical period , and likewise Demaillet and Buffon , with whose ...
x 페이지
... hand , we view ' Persistent Types ' in rela- tion to that hypothesis which supposes the species living at any time to be the result of the gradual modification of pre - existing species , a hypothesis which , though un- proven , and ...
... hand , we view ' Persistent Types ' in rela- tion to that hypothesis which supposes the species living at any time to be the result of the gradual modification of pre - existing species , a hypothesis which , though un- proven , and ...
15 페이지
... the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely て· under confinement ; and when , on the CHAP . I. ] 15 UNDER DOMESTICATION .
... the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely て· under confinement ; and when , on the CHAP . I. ] 15 UNDER DOMESTICATION .
16 페이지
... hand , we see individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by ...
... hand , we see individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by ...
43 페이지
... hand , nurserymen , from raising large stocks of the same plants , are generally far more successful than amateurs in getting new and valuable varieties . The keep- ing of a large number of individuals of a species in any country ...
... hand , nurserymen , from raising large stocks of the same plants , are generally far more successful than amateurs in getting new and valuable varieties . The keep- ing of a large number of individuals of a species in any country ...
기타 출판본 - 모두 보기
자주 나오는 단어 및 구문
accumulated adapted affinities allied species America amount ancient animals appear become bees believe birds breeds cause cells 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 intermediate land larvæ less living look male mammals manner migration modification modified descendants natural selection naturalists nearly nest offspring organic organisation perfect pigeons pistil plants pollen present probably produced progenitor ranked reciprocal crosses remarked resemble rudimentary seeds seems sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation varieties vary whole widely
인기 인용구
424 페이지 - 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.
63 페이지 - There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair.
79 페이지 - I may be allowed to personify the natural preservation or survival of the fittest, cares nothing for appearances, except in so far as they are useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good: Nature only for that of the being which she tends.
70 페이지 - I counted thirtytwo little trees ; and one of them, with twenty-six rings of growth, had during many years tried to raise its head above the stems of the heath, and had failed. No wonder that, as soon as the land was enclosed, it became thickly clothed with vigorously growing young firs. Yet the heath was so extremely barren and so extensive that no one would ever have imagined that cattle would have so closely and effectually searched it for food. Here we see that cattle absolutely determine the...
169 페이지 - 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.
63 페이지 - Hence as more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life.
167 페이지 - To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
378 페이지 - Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class, by utility or by the doctrine of final causes. The hopelessness of the attempt has been expressly admitted by Owen in his most interesting work on the 'Nature of Limbs.
187 페이지 - Under changed conditions of life, it is at least possible that slight modifications of instinct might be profitable to a species; and if it can be shown that instincts do vary ever so little, then I can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. It is thus, as I believe, that all the most complex and wonderful instincts have originated.
165 페이지 - I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.