The Origin of Species by Means of Natural Selection: Or, the Preservation of Favored Races in the Struggle for Life, Volumen1D. Appleton, 1898 |
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Página 11
... eggs . Many exotic plants have pollen utterly worthless , in the same con- dition as in the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under ...
... eggs . Many exotic plants have pollen utterly worthless , in the same con- dition as in the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under ...
Página 25
... state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The manner of flight , and in some breeds the voice and disposition , differ remarkably . CHAP . I. ] 25 DOMESTIC PIGEONS .
... state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The manner of flight , and in some breeds the voice and disposition , differ remarkably . CHAP . I. ] 25 DOMESTIC PIGEONS .
Página 77
... thus constantly destroying life ; or we forget how largely these songsters , or their eggs , or their nestlings , are destroyed by birds and beasts of prey ; we do not always bear in mind. CHAP . III . ] 77 STRUGGLE FOR EXISTENCE .
... thus constantly destroying life ; or we forget how largely these songsters , or their eggs , or their nestlings , are destroyed by birds and beasts of prey ; we do not always bear in mind. CHAP . III . ] 77 STRUGGLE FOR EXISTENCE .
Página 79
... eggs or seeds , must suffer destruction during some period of its life , and during some season or oc- casional year , otherwise , on the principle of geometri- cal increase , its numbers would quickly become so in- ordinately great ...
... eggs or seeds , must suffer destruction during some period of its life , and during some season or oc- casional year , otherwise , on the principle of geometri- cal increase , its numbers would quickly become so in- ordinately great ...
Página 81
... eggs and the ostrich a score , and yet in the same country the condor may be the more numerous of the two ; the Fulmar petrel lays but one egg , yet it is believed to be the most numerous bird in 4 the world . One fly deposits hundreds ...
... eggs and the ostrich a score , and yet in the same country the condor may be the more numerous of the two ; the Fulmar petrel lays but one egg , yet it is believed to be the most numerous bird in 4 the world . One fly deposits hundreds ...
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Términos y frases comunes
adapted advantage allied analogous animals and plants appear Asa Gray beak become bees believe birds breeds caudicle cause cells characters climate closely colour common crossed cuckoo degree descendants developed difficulty distinct species disuse divergence domestic animals domestic races doubt effects eggs existence extinct extremely facts favourable females flowers forms Fritz Müller genera genus giraffe gradations greater number groups habits Hence hermaphrodites hive-bee important increase inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ large number larger genera larvæ less males manner Melipona Mivart modified natural selection naturalists nearly nest occasionally offspring organisation organs origin Origin of Species parent perfect period pigeons pollen pollen-grains present preserved prey principle probably produced progenitor quadrupeds rank rarely Red Grouse relation remarked resemble rock-pigeon seeds sexes sexual selection slight stamens striped structure struggle supposed swimbladder tend tendency tion tree variability variations varieties vary widely wings young