On the Origin of Species by Means of Natural Selection; Or, The Preservation of Favoured Races in the Struggle for LifeD. Appleton, 1861 - Всего страниц: 440 |
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Стр. 15
... male and female reproductive elements having been affected prior to the act of conception . Several reasons make me believe in this ; but the chief one is the remarkable effect which confinement or cultivation has on the functions of ...
... male and female reproductive elements having been affected prior to the act of conception . Several reasons make me believe in this ; but the chief one is the remarkable effect which confinement or cultivation has on the functions of ...
Стр. 19
... males of our domestic breeds are often transmitted either ex- clusively , or in a much greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life peculiarity first ...
... males of our domestic breeds are often transmitted either ex- clusively , or in a much greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life peculiarity first ...
Стр. 20
... male element ; in nearly the same manner as in the crossed offspring from a short- horned cow by a long - horned bull , the greater length of horn , though appearing late in life , is clearly due to the male element . Having alluded to ...
... male element ; in nearly the same manner as in the crossed offspring from a short- horned cow by a long - horned bull , the greater length of horn , though appearing late in life , is clearly due to the male element . Having alluded to ...
Стр. 26
... male bird , is also remarkable from the wonderful develop- ment of the carunculated skin above the head , and this is accompanied by greatly elongated eyelids , very large ex- ternal orifices to the nostrils , and a wide gape of mouth ...
... male bird , is also remarkable from the wonderful develop- ment of the carunculated skin above the head , and this is accompanied by greatly elongated eyelids , very large ex- ternal orifices to the nostrils , and a wide gape of mouth ...
Стр. 27
... males and females have come to differ to a slight degree from each other . Altogether at least a score of pigeons might be chosen , which if shown to an ornithologist , and he were told that they were wild birds , would certainly , I ...
... males and females have come to differ to a slight degree from each other . Altogether at least a score of pigeons might be chosen , which if shown to an ornithologist , and he were told that they were wild birds , would certainly , I ...
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On the Origin of Species by Means of Natural Selection: Or The ..., Том 2 Charles Darwin Полный просмотр - 1888 |
Часто встречающиеся слова и выражения
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 larvæ laws 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
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Стр. 9 - 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 be excused for entering on these personal details, as I give them to show that I have not been hasty in coming to a decision.
Стр. 76 - When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.
Стр. 171 - 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.
Стр. 9 - Beagle,' as naturalist, I was much struck with certain facts in the distribution of the organic beings inhabiting South America, and in the geological relations of the present to the past inhabitants of that continent.
Стр. 70 - Firs on the distant hill-tops ; within the last ten years large spaces have been enclosed, and self-sown firs are now springing up in multitudes, so close together that all cannot live. When I ascertained that these young trees had not been sown or planted, I was so much surprised at their numbers that I went to several points of view, whence I could examine hundreds of acres of the unenclosed heath, and literally I could not see a single Scotch Fir, except the old planted clumps.
Стр. 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." Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district!
Стр. 72 - Newman, who has long attended to the habits of humble-bees, believes that " more than two-thirds of them are thus destroyed all over England.
Стр. 169 - 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.
Стр. 423 - Hereafter we shall be compelled to acknowledge that the only distinction between species and well-marked varieties is, that the latter are known, or believed to be connected at the present day by intermediate gradations whereas species were formerly thus connected.
Стр. 212 - This difficulty, though appearing insuperable, is lessened, or, as I believe, disappears, when it is remembered that selection may be applied to the family, as well as to the individual, and may thus gain the desired end. Thus, a well-flavoured vegetable is cooked, and the individual is destroyed; but the horticulturist sows seeds of the same stock, and confidently expects to get nearly the same variety; breeders of cattle wish the flesh and fat to be well marbled together; the animal has been slaughtered,...