The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Том 1D. Appleton & Company, 1889 |
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Стр. 114
... stamens and pistils placed , in relation to the size and habits of the particular insect which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured . We might have taken the case of ...
... stamens and pistils placed , in relation to the size and habits of the particular insect which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured . We might have taken the case of ...
Стр. 115
... stamens produ- cing a rather small quantity of pollen , and a rudimentary pistil ; other holly - trees bear only female flowers ; these have a full - sized pistil , and four stamens with shrivelled anthers , in which not a grain of ...
... stamens produ- cing a rather small quantity of pollen , and a rudimentary pistil ; other holly - trees bear only female flowers ; these have a full - sized pistil , and four stamens with shrivelled anthers , in which not a grain of ...
Стр. 116
... stamens alone in one flower or on one whole plant , and pistils alone in another flower or on another plant . In plants under culture and placed under new conditions of life , sometimes the male organs and some- times the female organs ...
... stamens alone in one flower or on one whole plant , and pistils alone in another flower or on another plant . In plants under culture and placed under new conditions of life , sometimes the male organs and some- times the female organs ...
Стр. 120
... stamens of a flower suddenly spring towards the pistil , or slowly move one after the other towards it , the contrivance seems adapted solely to ensure sclf- fertilisation ; and no doubt it is useful for this 120 [ CHAP . IV . ON THE ...
... stamens of a flower suddenly spring towards the pistil , or slowly move one after the other towards it , the contrivance seems adapted solely to ensure sclf- fertilisation ; and no doubt it is useful for this 120 [ CHAP . IV . ON THE ...
Стр. 121
... stamens to spring forward , as Kölreuter has shown to be the case with the barberry ; and in this very genus , which seems to have a special contrivance for self - fertilisation , it is well known that , if closely - allied forms or ...
... stamens to spring forward , as Kölreuter has shown to be the case with the barberry ; and in this very genus , which seems to have a special contrivance for self - fertilisation , it is well known that , if closely - allied forms or ...
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The Origin of Species by Means of Natural Selection: Or, the ..., Том 1 Charles Darwin Полный просмотр - 1898 |
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adapted advantage allied analogous animals and plants appear Asa Gray beak become bees believe birds breeds caudicle cause cells characters climate closely Cloth colour common crossed cuckoo degree descendants developed difficulty distinct species disuse domestic animals domestic races doubt effects eggs existence extinct extremely facts favourable females flowers forms Fritz Müller genera genus gradations greater number groups habits Hence hermaphrodites hive-bee important improved inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ large number larger genera larvæ less likewise males manner Mivart modified natural selection naturalists nearly nest neuters occasionally offspring organisation organs origin ORIGIN OF SPECIES parent perfect period pigeons pollen pollen-grains present preserved principle probably produced progenitor quadrupeds rank Red Grouse remarked resemble rock-pigeon seeds sexes sexual sexual selection slight stamens structure struggle sub-breeds supposed swimbladder tend tendency tion transitional tree tumbler pigeon variability variations varieties vary widely wild wings young
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Стр. 227 - If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection.
Стр. 203 - 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. 75 - Several writers have misapprehended or objected to the term Natural Selection, Some have even imagined that natural selection induces variability, whereas it' implies only the. preservation of such variations as arise and are beneficial to the being under its conditions of * life.
Стр. xxv - As many more individuals of each species are born than can possibly survive ; and as, consequently, there is a frequently recurring straggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected.
Стр. xix - 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.
Стр. 144 - It is well known that several animals, belonging to the most different classes, which inhabit the caves of Carniola and of Kentucky, are blind. In some of the crabs the foot-stalk for the eye remains, though the eye is gone; — the stand for the telescope is there, though the telescope with its glasses has been lost. As it is difficult to imagine that eyes, though useless, could be in any way injurious to animals living in darkness, their loss may be attributed to disuse.
Стр. 55 - Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult — at least I have found it so — than constantly to bear this conclusion in mind.
Стр. 341 - Cloth, $2.00. DIFFERENT FORMS OF FLOWERS ON PLANTS OF THE SAME SPECIES. With Illustrations. 12mo. Cloth, $1.50. THE POWER OF MOVEMENT IN PLANTS. By CHARLES DARWIN, LL. D., FRS, assisted by FRANCIS DARWIN.
Стр. 140 - The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was small, budding twigs; and this connection of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups.
Стр. 140 - The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth. The green and budding twigs may represent existing species ; and those produced during each former year may represent the long succession of extinct species.