On the Origin of Species by Means of Natural Selection, Or, The Preservation of Favoured Races in the Struggle for Life |
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Page vii
... hybrids- Sterility various in degree , not universal , affected by close inter- breeding , removed by domestication - Laws governing the sterility of hybrids - Sterility not a special endowment , but incidental on other differences ...
... hybrids- Sterility various in degree , not universal , affected by close inter- breeding , removed by domestication - Laws governing the sterility of hybrids - Sterility not a special endowment , but incidental on other differences ...
Page 9
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under con- finement ; and when , on the other hand , we see indivi- duals , though taken young from a ...
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under con- finement ; and when , on the other hand , we see indivi- duals , though taken young from a ...
Page 27
... hybrids or mongrels from between all the domestic breeds of pigeons are perfectly fertile . I can state this from my ... hybrid offspring of two animals clearly distinct being them- selves perfectly fertile . Some authors believe that ...
... hybrids or mongrels from between all the domestic breeds of pigeons are perfectly fertile . I can state this from my ... hybrid offspring of two animals clearly distinct being them- selves perfectly fertile . Some authors believe that ...
Page 44
... hybrids and mongrels , and the frequent sterility of hybrids ; but the cases of plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change I am convinced that ...
... hybrids and mongrels , and the frequent sterility of hybrids ; but the cases of plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change I am convinced that ...
Page 49
... hybrid nature of the intermediate links always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the intermediate links have actually been found , but because analogy leads ...
... hybrid nature of the intermediate links always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the intermediate links have actually been found , but because analogy leads ...
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Common terms and phrases
accumulated adapted affinities allied species America amount analogous ancient animals appear Asa Gray become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo 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 hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing intermediate land larvæ laws less living male mammals manner Marsupials migration modification modified descendants mongrels natural selection naturalists nearly nest occasionally offspring organisation origin of species perfect pigeons plants pollen present principle probably produced progenitor racter ranked reciprocal crosses remarked resemble rudimentary organs seeds Silurian slight South America sterility structure struggle successive supposed tend theory tion variability variations varieties vary whole widely