The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1898 |
Dentro del libro
Resultados 1-5 de 35
Página 7
... similar experiments during many years , and always with the same result . These cases serve to show on what slight and mysterious causes the lesser or greater fertility of a species some- times depends . The practical experiments of ...
... similar experiments during many years , and always with the same result . These cases serve to show on what slight and mysterious causes the lesser or greater fertility of a species some- times depends . The practical experiments of ...
Página 26
... similar manner . In the one case , the conditions of life have been dis- turbed , though often in so slight a degree as to be in- appreciable by us ; in the other case , or that of hybrids , the external conditions have remained the ...
... similar manner . In the one case , the conditions of life have been dis- turbed , though often in so slight a degree as to be in- appreciable by us ; in the other case , or that of hybrids , the external conditions have remained the ...
Página 27
... similar parallelism holds good with an allied yet very different class of facts . It is an old and almost universal belief founded on a considerable body of evi- dence , which I have elsewhere given , that slight changes in the ...
... similar parallelism holds good with an allied yet very different class of facts . It is an old and almost universal belief founded on a considerable body of evi- dence , which I have elsewhere given , that slight changes in the ...
Página 32
... similar cases occur with the illegitimate off- spring of various dimorphic and trimorphic plants . Altogether there is the closest identity in character and behaviour between illegitimate plants and hybrids . It is hardly an ...
... similar cases occur with the illegitimate off- spring of various dimorphic and trimorphic plants . Altogether there is the closest identity in character and behaviour between illegitimate plants and hybrids . It is hardly an ...
Página 35
... similar differences in the case of varieties would be no sure guide . It is certain that with species the cause lies exclusively in differences in their sexual constitution . Now the varying conditions to which domesticated animals and ...
... similar differences in the case of varieties would be no sure guide . It is certain that with species the cause lies exclusively in differences in their sexual constitution . Now the varying conditions to which domesticated animals and ...
Otras ediciones - Ver todas
Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe belonging birds Cambrian changes characters cies classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo eral Europe existing extinct fact faunas fertilised fertility flowers formations formerly forms fossil fresh-water Fritz Müller Gärtner genera genus geological period geological record Glacial period groups of species habits hybrids hybrids produced important inhabitants inherited insects instance intermediate intervals land larvæ less living mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation palæontologists Palæozoic parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst whole widely different wings