On the Origin of Species by Means of Natural Selection, Or, The Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 - Всего страниц: 432 |
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Стр. 2
... plants and animals ; though the formative organs themselves are perfect in structure , as far as the microscope reveals . In the first case the two sexual elements which go to form the embryo are per- fect ; in the second case they are ...
... plants and animals ; though the formative organs themselves are perfect in structure , as far as the microscope reveals . In the first case the two sexual elements which go to form the embryo are per- fect ; in the second case they are ...
Стр. 3
... plants . Nearly all the plants experimented on by Gärtner were potted , and were kept in a chamber in his house . That these processes are often injurious to the fertility of a plant cannot be doubted ; for Gärtner gives in his table ...
... plants . Nearly all the plants experimented on by Gärtner were potted , and were kept in a chamber in his house . That these processes are often injurious to the fertility of a plant cannot be doubted ; for Gärtner gives in his table ...
Стр. 5
... plants are already affected in some degree . But I believe that their fertility has been di- minished in nearly all these cases by an independent cause , namely , by too close interbreeding . I have made so many experiments and ...
... plants are already affected in some degree . But I believe that their fertility has been di- minished in nearly all these cases by an independent cause , namely , by too close interbreeding . I have made so many experiments and ...
Стр. 6
... plant , would be thus effected . Moreover , whenever complicated experiments are in progress , so careful an observer as Gärtner would have castrated his hybrids , and this would have ensured ... plants of certain 6 [ CHAP . IX . HYBRIDISM .
... plant , would be thus effected . Moreover , whenever complicated experiments are in progress , so careful an observer as Gärtner would have castrated his hybrids , and this would have ensured ... plants of certain 6 [ CHAP . IX . HYBRIDISM .
Стр. 7
... plant , though this pollen can be proved to be perfectly sound by fertilising other plants or species . In the genus Hippeastrum , in Cory- dalis as shown by Professor Hildebrand , in various or- chids as shown by Mr. Scott and Fritz ...
... plant , though this pollen can be proved to be perfectly sound by fertilising other plants or species . In the genus Hippeastrum , in Cory- dalis as shown by Professor Hildebrand , in various or- chids as shown by Mr. Scott and Fritz ...
Другие издания - Просмотреть все
The Origin of Species by Means of Natural Selection: Or, The ..., Том 1 Charles Darwin Полный просмотр - 1889 |
The Origin of Species by Means of Natural Selection: Or, the ..., Том 1 Charles Darwin Полный просмотр - 1898 |
Часто встречающиеся слова и выражения
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