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 22
... similar changes of structure . [ Nevertheless some slight amount of change may , I think , be attributed to the direct action of the conditions of life - as , in some cases , increased size from amount of food , colour from particular ...
... similar changes of structure . [ Nevertheless some slight amount of change may , I think , be attributed to the direct action of the conditions of life - as , in some cases , increased size from amount of food , colour from particular ...
Página 32
... similar habits with the rock - pigeon seems to me a very rash assump- tion . Moreover , the several above - named domesticated breeds have been transported to all parts of the world , and , therefore , some of them must have been ...
... similar habits with the rock - pigeon seems to me a very rash assump- tion . Moreover , the several above - named domesticated breeds have been transported to all parts of the world , and , therefore , some of them must have been ...
Página 36
... similar conclusion in regard to the many species of finches , or other large groups of birds , in nature . One circumstance has struck me much ; namely , that nearly all the breeders of the various domestic animals and the cultivators ...
... similar conclusion in regard to the many species of finches , or other large groups of birds , in nature . One circumstance has struck me much ; namely , that nearly all the breeders of the various domestic animals and the cultivators ...
Página 41
... similar process of selection , and by careful training , the whole body of English racehorses have come to surpass in fleetness and size the parent Arab stock , so 73 — B * that the latter , by the regulations for the Goodwood ...
... similar process of selection , and by careful training , the whole body of English racehorses have come to surpass in fleetness and size the parent Arab stock , so 73 — B * that the latter , by the regulations for the Goodwood ...
Página 52
... similar to some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as distinct species , are in several respects the most important for us . We have every reason to ...
... similar to some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as distinct species , are in several respects the most important for us . We have every reason to ...
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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