On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeD. Appleton, 1909 - 430 páginas |
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Página 7
... plants - Nature of the checks to increase - Com- petition universal - Effects of Climate - Protection from the number of individuals - Complex relations of all animals and 7 61 plants throughout nature - Struggle for life most severe ...
... plants - Nature of the checks to increase - Com- petition universal - Effects of Climate - Protection from the number of individuals - Complex relations of all animals and 7 61 plants throughout nature - Struggle for life most severe ...
Página 15
... plant itself . It is , therefore , of the highest importance to gain a clear insight into the means of modification ... plants would offer the best chance of making out this obscure problem . Nor have I been disappointed ; in this and ...
... plant itself . It is , therefore , of the highest importance to gain a clear insight into the means of modification ... plants would offer the best chance of making out this obscure problem . Nor have I been disappointed ; in this and ...
Página 19
... plants and animals , one of the first points which strikes us , is , that they generally differ more from each other than do the individuals of any one species or variety in a state of nature . When we reflect on the vast diversity of ...
... plants and animals , one of the first points which strikes us , is , that they generally differ more from each other than do the individuals of any one species or variety in a state of nature . When we reflect on the vast diversity of ...
Página 20
... plants have pollen utterly worthless , in the same exact condition as in the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under con ...
... plants have pollen utterly worthless , in the same exact condition as in the most sterile hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under con ...
Página 21
... plants withstand domestication or cultivation , and vary very slightly - perhaps hardly more than in a state of nature . 66 " " A long list could easily be given of " sporting plants ; by this term gardeners mean a single bud or offset ...
... plants withstand domestication or cultivation , and vary very slightly - perhaps hardly more than in a state of nature . 66 " " A long list could easily be given of " sporting plants ; by this term gardeners mean a single bud or offset ...
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Términos y frases comunes
accumulated adapted affinities allied species America analogous ancient animals appear archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo endemic existing exterminated extinct extremely facts favourable fertilised 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 increase individuals inhabitants inherited insects instance instincts intercrossing intermediate larvæ laws less living males mammals manner migration modification modified descendants natural selection naturalists nearly nest occasionally offspring organic organisation origin of species perfect pigeons plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary seeds sexual sexual selection Silurian slight sometimes South America sterility structure struggle successive supposed swimbladder tend theory variability variations varieties vary whole widely