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 8
... reasons make me believe in this ; but the chief one is the remarkable effect which confine- ment or cultivation has on the function of the repro- ductive system ; this system appearing to be far more susceptible than any other part of ...
... reasons make me believe in this ; but the chief one is the remarkable effect which confine- ment or cultivation has on the function of the repro- ductive system ; this system appearing to be far more susceptible than any other part of ...
Página 13
... reason why a peculiarity should appear at any particular age , yet that it does tend to appear in the offspring at the same period at which it first appeared in the parent . I believe this . rule to be of the highest importance in ...
... reason why a peculiarity should appear at any particular age , yet that it does tend to appear in the offspring at the same period at which it first appeared in the parent . I believe this . rule to be of the highest importance in ...
Página 17
... reasons which I cannot give here , I am doubtfully inclined to believe , in opposition to several authors , that all the races have descended from one wild stock . Mr. Blyth , whose opinion , from his large and varied stores of ...
... reasons which I cannot give here , I am doubtfully inclined to believe , in opposition to several authors , that all the races have descended from one wild stock . Mr. Blyth , whose opinion , from his large and varied stores of ...
Página 21
... reasons which have led me to this belief are in some degree applicable in other cases , I will here briefly give them . If the several breeds are not varieties , and have not proceeded from the rock - pigeon , they must have descended ...
... reasons which have led me to this belief are in some degree applicable in other cases , I will here briefly give them . If the several breeds are not varieties , and have not proceeded from the rock - pigeon , they must have descended ...
Página 25
... reasons , namely , the improbability of man having formerly got seven or eight supposed species of pigeons to breed freely under domestica- tion ; these supposed species being quite unknown in a wild state , and their becoming nowhere ...
... reasons , namely , the improbability of man having formerly got seven or eight supposed species of pigeons to breed freely under domestica- tion ; these supposed species being quite unknown in a wild state , and their becoming nowhere ...
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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