The Origin of Species by Means of Natural Selection: Or the Preservation of Favored Races in the Struggle for LifeD. Appleton, 1904 - 435 páginas |
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Página x
... hybrid moths . The discussion on the fertility of hybrids not having been acquired through natural selection condensed and modified . Fifth Sixth Edition . Edition . Chief Additions and Corrections X ADDITIONS AND CORRECTIONS .
... hybrid moths . The discussion on the fertility of hybrids not having been acquired through natural selection condensed and modified . Fifth Sixth Edition . Edition . Chief Additions and Corrections X ADDITIONS AND CORRECTIONS .
Página xi
... hybrids , added to and corrected . Pyrgoma found in the chalk . Extinct forms serving to connect existing groups . On earth adhering to the feet of migratory birds . On the wide geographical range of a species of Galaxias , a fresh ...
... hybrids , added to and corrected . Pyrgoma found in the chalk . Extinct forms serving to connect existing groups . On earth adhering to the feet of migratory birds . On the wide geographical range of a species of Galaxias , a fresh ...
Página 5
... Hybrid- ism , or the infertility of species and the fertility of varieties when intercrossed ; and fourthly , the imperfec- tion of the Geological Record . In the next chapter I shall consider the geological succession of organic beings ...
... Hybrid- ism , or the infertility of species and the fertility of varieties when intercrossed ; and fourthly , the imperfec- tion of the Geological Record . In the next chapter I shall consider the geological succession of organic beings ...
Página 11
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature ...
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature ...
Página 30
... hybrids or mongrels from between all the breeds of the pigeon are perfectly fertile , as I can state from my own observations , purposely made , on the most distinct breeds . Now , hardly any cases have been ascertained with certainty ...
... hybrids or mongrels from between all the breeds of the pigeon are perfectly fertile , as I can state from my own observations , purposely made , on the most distinct breeds . Now , hardly any cases have been ascertained with certainty ...
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Términos y frases comunes
adapted affinities allied species America ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common continent crossed crustaceans degree developed difficulty distinct species domestic doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living males mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs parent peculiar perfect pigeon pistil pollen present principle probably produced progenitor quadrupeds ranked remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed swimbladder tend theory tion trees variability variations varieties vary whilst whole wings young