The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 - 432페이지 |
도서 본문에서
85개의 결과 중 1 - 5개
2 페이지
... 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 either not ...
... 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 either not ...
8 페이지
... animals , much fewer experiments have been carefully tried than with plants . If our systematic arrangements can be trusted , that is , if the genera of animals are as distinct from each other as are the genera of plants , then we may ...
... animals , much fewer experiments have been carefully tried than with plants . If our systematic arrangements can be trusted , that is , if the genera of animals are as distinct from each other as are the genera of plants , then we may ...
9 페이지
... animals , I hardly know of an in- stance in which two families of the same hybrid have been raised at the same time from different parents , so as to avoid the ill effects of close interbreeding . On the contrary , brothers and sisters ...
... animals , I hardly know of an in- stance in which two families of the same hybrid have been raised at the same time from different parents , so as to avoid the ill effects of close interbreeding . On the contrary , brothers and sisters ...
10 페이지
... animals , the various races when crossed together are quite fertile ; yet in many cases they are descended from two or more wild species . From this fact we must conclude either that the abo- riginal parent - species at first produced ...
... animals , the various races when crossed together are quite fertile ; yet in many cases they are descended from two or more wild species . From this fact we must conclude either that the abo- riginal parent - species at first produced ...
11 페이지
... animals , and , considering how scanty our knowledge is in regard to hybrid animals , I have been surprised to find how generally the same rules apply to both king- doms . It has been already remarked , that the degree of fertility ...
... animals , and , considering how scanty our knowledge is in regard to hybrid animals , I have been surprised to find how generally the same rules apply to both king- doms . It has been already remarked , that the degree of fertility ...
기타 출판본 - 모두 보기
자주 나오는 단어 및 구문
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