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 16
... single species , then such facts would have great weight in making us doubt about the immutability of the many very closely - allied natural species - for instance , of the many foxes - inhabiting different quarters of the world . I do ...
... single species , then such facts would have great weight in making us doubt about the immutability of the many very closely - allied natural species - for instance , of the many foxes - inhabiting different quarters of the world . I do ...
Página 17
... single species alone should have been domesticated . In regard to sheep and goats I can form no opinion . I should think , from facts communicated to me by Mr. Blyth , on the habits , voice , and con- stitution , etc. , of the humped ...
... single species alone should have been domesticated . In regard to sheep and goats I can form no opinion . I should think , from facts communicated to me by Mr. Blyth , on the habits , voice , and con- stitution , etc. , of the humped ...
Página 19
... single case on record of a permanent race having been thus formed . On the Breeds of the Domestic Pigeon . - Believing that it is always best to study some special group , I have , after deliberation , taken up domestic pigeons . I have ...
... single case on record of a permanent race having been thus formed . On the Breeds of the Domestic Pigeon . - Believing that it is always best to study some special group , I have , after deliberation , taken up domestic pigeons . I have ...
Página 24
... closely related together , though it is unsupported by a single experiment . But to ex- tend the hypothesis so far as to suppose that species , aboriginally as distinct as carriers , tumblers , pouters , 24 ON THE ORIGIN OF SPECIES.
... closely related together , though it is unsupported by a single experiment . But to ex- tend the hypothesis so far as to suppose that species , aboriginally as distinct as carriers , tumblers , pouters , 24 ON THE ORIGIN OF SPECIES.
Página 28
... single lifetime , modified to a large extent some breeds of cattle and sheep . order fully to realise what they have done , it is almost necessary to read several of the many treatises devoted to this subject , and to inspect the ...
... single lifetime , modified to a large extent some breeds of cattle and sheep . order fully to realise what they have done , it is almost necessary to read several of the many treatises devoted to this subject , and to inspect the ...
Otras ediciones - Ver todas
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