On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 50
... tend to obscure this result , that I am surprised that my tables show even a small majority on the side of the larger genera . I will here allude to only two causes of obscurity . Fresh - water and salt- loving plants have generally ...
... tend to obscure this result , that I am surprised that my tables show even a small majority on the side of the larger genera . I will here allude to only two causes of obscurity . Fresh - water and salt- loving plants have generally ...
Página 53
... tend to increase into the greater differ- ences between species . There is one other point which seems to me worth notice . Varieties generally have much restricted ranges : this statement is indeed scarcely more than a truism , for if ...
... tend to increase into the greater differ- ences between species . There is one other point which seems to me worth notice . Varieties generally have much restricted ranges : this statement is indeed scarcely more than a truism , for if ...
Página 55
... tend to become converted into new and distinct species . The larger genera thus tend to become larger ; and throughout nature the forms of life which are now dominant tend to become still more dominant by leaving many modified and ...
... tend to become converted into new and distinct species . The larger genera thus tend to become larger ; and throughout nature the forms of life which are now dominant tend to become still more dominant by leaving many modified and ...
Página 57
... tend to the preservation of that individual , and will generally be inherited by its offspring . The off- spring , also , will thus have a better chance of surviving , for , of the many individuals of any species which are periodically ...
... tend to the preservation of that individual , and will generally be inherited by its offspring . The off- spring , also , will thus have a better chance of surviving , for , of the many individuals of any species which are periodically ...
Página 59
... tend to increase . Every being , which during its natural lifetime produces several eggs or seeds , must suffer destruction during some period of its life , and during some season or occa- sional year , otherwise , on the principle of ...
... tend to increase . Every being , which during its natural lifetime produces several eggs or seeds , must suffer destruction during some period of its life , and during some season or occa- sional year , otherwise , on the principle of ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic 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 hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely