The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1898 |
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Página 3
... gives in his table about a score of cases of plants which he castrated , and artificially fertilised with their own pollen , and ( ex- cluding all cases such as the Leguminosa , in which there is an acknowledged difficulty in the ...
... gives in his table about a score of cases of plants which he castrated , and artificially fertilised with their own pollen , and ( ex- cluding all cases such as the Leguminosa , in which there is an acknowledged difficulty in the ...
Página 6
... give only a single one as an ex- ample , namely , that " every ovule in a pod of Crinum capense fertilised by C. revolutum produced a plant , which I never saw to occur in a case of its natural fecun- dation . " So that here we have ...
... give only a single one as an ex- ample , namely , that " every ovule in a pod of Crinum capense fertilised by C. revolutum produced a plant , which I never saw to occur in a case of its natural fecun- dation . " So that here we have ...
Página 7
... give one instance , a bulb of Hippeastrum aulicum produced four flowers ; three were fertilised by Herbert with their own pollen , and the fourth was subsequently fertilised by the pollen of a compound hybrid descended from three ...
... give one instance , a bulb of Hippeastrum aulicum produced four flowers ; three were fertilised by Herbert with their own pollen , and the fourth was subsequently fertilised by the pollen of a compound hybrid descended from three ...
Página 11
... give up the belief of the universal sterility of species when crossed ; or we must look at this sterility in animals , not as an indelible characteristic , but as one capable of being removed by domestication . Finally , considering all ...
... give up the belief of the universal sterility of species when crossed ; or we must look at this sterility in animals , not as an indelible characteristic , but as one capable of being removed by domestication . Finally , considering all ...
Página 15
... give an instance : Mirabilis jalapa can easily be fertilised by the pollen of M. longiflora , and the hybrids thus produced are suffi- ciently fertile ; but Kölreuter tried more than two hun- dred times , during eight following years ...
... give an instance : Mirabilis jalapa can easily be fertilised by the pollen of M. longiflora , and the hybrids thus produced are suffi- ciently fertile ; but Kölreuter tried more than two hun- dred times , during eight following years ...
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Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe belonging birds Cambrian changes characters cies classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo eral Europe existing extinct fact faunas fertilised fertility flowers formations formerly forms fossil fresh-water Fritz Müller Gärtner genera genus geological period geological record Glacial period groups of species habits hybrids hybrids produced important inhabitants inherited insects instance intermediate intervals land larvæ less living mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation palæontologists Palæozoic parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst whole widely different wings