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 |
Dentro del libro
Página 158
... continuous area , are generally so distributed that each has a wide range , with a comparatively narrow neutral territory between them , in which they become rather suddenly rarer and rarer ; then , as varieties do not essentially ...
... continuous area , are generally so distributed that each has a wide range , with a comparatively narrow neutral territory between them , in which they become rather suddenly rarer and rarer ; then , as varieties do not essentially ...
Página 160
... continuous must often have existed within the recent period in isolated portions , in which many forms , more especially amongst the classes which unite for each birth and wander much , may have separately been rendered sufficiently ...
... continuous must often have existed within the recent period in isolated portions , in which many forms , more especially amongst the classes which unite for each birth and wander much , may have separately been rendered sufficiently ...
Página 183
... continuous area , must often have been formed when the area was not continuous , and when the conditions of life did not insensibly graduate away from one part to another . When two varieties are formed in two districts of a continuous ...
... continuous area , must often have been formed when the area was not continuous , and when the conditions of life did not insensibly graduate away from one part to another . When two varieties are formed in two districts of a continuous ...
Página 250
... continuous area with graduated physical conditions . I endeavoured to show , that the life of each species depends in a more important manner on the presence of other already defined organic forms , than on climate ; and , therefore ...
... continuous area with graduated physical conditions . I endeavoured to show , that the life of each species depends in a more important manner on the presence of other already defined organic forms , than on climate ; and , therefore ...
Página 283
... single species , changing more or less quickly , and in a greater or lesser degree . A group does not reappear after it has once disappeared ; or its existence , as long as it lasts , is continuous GEOLOGICAL SUCCESSION 283.
... single species , changing more or less quickly , and in a greater or lesser degree . A group does not reappear after it has once disappeared ; or its existence , as long as it lasts , is continuous GEOLOGICAL SUCCESSION 283.
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
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