On the Origin of Species by Means of Natural Selection, Or, The Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 |
Dentro del libro
Resultados 6-10 de 53
Página 5
... Hybrids are seldom raised by experimentalists in great numbers ; and as the parent - species , or other allied hybrids , generally grow in the same garden , the visits of insects must be carefully prevented during the flowering season ...
... Hybrids are seldom raised by experimentalists in great numbers ; and as the parent - species , or other allied hybrids , generally grow in the same garden , the visits of insects must be carefully prevented during the flowering season ...
Página 6
... hybrids , and this would have ensured in each generation a cross with pollen from a distinct flower , either from the same plant or from another plant of the same hybrid nature . And thus , the strange fact of an increase of fertility ...
... hybrids , and this would have ensured in each generation a cross with pollen from a distinct flower , either from the same plant or from another plant of the same hybrid nature . And thus , the strange fact of an increase of fertility ...
Página 7
... hybrid descended from three distinct species : the result was that the ovaries of the three first flowers soon ceased ... hybrids seed freely . For instance , Herbert asserts that 66 a hybrid from Calceolaria integrifolia and plantaginea ...
... hybrid descended from three distinct species : the result was that the ovaries of the three first flowers soon ceased ... hybrids seed freely . For instance , Herbert asserts that 66 a hybrid from Calceolaria integrifolia and plantaginea ...
Página 8
... hybrid between Rhod . ponticum and catawbiense , and that this hybrid " seeds as freely as it is possible to imagine . " Had hybrids when fairly treated , always gone on decreasing in fertility in each . successive generation , as ...
... hybrid between Rhod . ponticum and catawbiense , and that this hybrid " seeds as freely as it is possible to imagine . " Had hybrids when fairly treated , always gone on decreasing in fertility in each . successive generation , as ...
Página 9
... hybrids should have gone on increas- ing . Although I know of hardly any thoroughly well- authenticated cases of perfectly fertile hybrid animals , I have reason to believe that the hybrids from Cervulus vaginalis and Reevesii , and ...
... hybrids should have gone on increas- ing . Although I know of hardly any thoroughly well- authenticated cases of perfectly fertile hybrid animals , I have reason to believe that the hybrids from Cervulus vaginalis and Reevesii , and ...
Otras ediciones - Ver todas
Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe birds Cambrian changes characters cies classification climate closely allied common progenitor 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 individuals 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 parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs sediment seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst widely different wings