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 10
... forms of life throughout the world - On the affinities of extinct species to each other and to living species - On the state of development of ancient forms- On the succession of the same types within the same areas— Summary of ...
... forms of life throughout the world - On the affinities of extinct species to each other and to living species - On the state of development of ancient forms- On the succession of the same types within the same areas— Summary of ...
Página 52
... forms which possess in some considerable degree the character of species , but which are so closely similar to some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as ...
... forms which possess in some considerable degree the character of species , but which are so closely similar to some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as ...
Página 53
... forms ! Amongst animals which unite for each birth , and which are highly locomotive , doubtful forms , ranked by one zoologist as a species and by another as a variety , can rarely be found within the same country , but are common in ...
... forms ! Amongst animals which unite for each birth , and which are highly locomotive , doubtful forms , ranked by one zoologist as a species and by another as a variety , can rarely be found within the same country , but are common in ...
Página 54
... forms , considered by highly - competent judges as varieties , have so perfectly the character of species that they are ranked by other highly - competent judges as good and true species . But to discuss whether such slightly different ...
... forms , considered by highly - competent judges as varieties , have so perfectly the character of species that they are ranked by other highly - competent judges as good and true species . But to discuss whether such slightly different ...
Página 55
... forms . His general tendency will be to make many species , for he will become impressed , just like the pigeon or poultry fancier before alluded to , with the amount of difference in the forms which he is continually studying ; and he ...
... forms . His general tendency will be to make many species , for he will become impressed , just like the pigeon or poultry fancier before alluded to , with the amount of difference in the forms which he is continually studying ; and he ...
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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