The Origin of Species by Means of Natural Selection, Or, The Preservation of Favored Races in the Struggle for Life, 2권D. Appleton, 1896 |
도서 본문에서
38개의 결과 중 1 - 5개
20 페이지
... separated species to have been rendered mutually sterile , and consequently this could not have been effected through natural selection ; but it may perhaps be argued , that , if a 20 CAUSES OF THE STERILITY [ CHAP . IX .
... separated species to have been rendered mutually sterile , and consequently this could not have been effected through natural selection ; but it may perhaps be argued , that , if a 20 CAUSES OF THE STERILITY [ CHAP . IX .
37 페이지
... separated sexes , they never naturally crossed . He then fertilised thirteen flowers of the one kind with pollen of the other ; but only a single head produced any seed , and this one head produced only five grains . Manipulation in ...
... separated sexes , they never naturally crossed . He then fertilised thirteen flowers of the one kind with pollen of the other ; but only a single head produced any seed , and this one head produced only five grains . Manipulation in ...
38 페이지
... separated sexes , and he asserts that their mutual fertilisation is by so much the less easy as their differences are greater . How far these experiments may be trusted , I know not ; but the forms experimented on are ranked by Sageret ...
... separated sexes , and he asserts that their mutual fertilisation is by so much the less easy as their differences are greater . How far these experiments may be trusted , I know not ; but the forms experimented on are ranked by Sageret ...
60 페이지
... separated from each other by wide intervals of time . This doctrine has been emphatically admitted by many geologists and palæontologists , who , like E. Forbes , entirely disbelieve in the change of species . When we see the formations ...
... separated from each other by wide intervals of time . This doctrine has been emphatically admitted by many geologists and palæontologists , who , like E. Forbes , entirely disbelieve in the change of species . When we see the formations ...
71 페이지
... fossils , though universally ranked as specifically different , yet are far more closely related to each other than are the species found in more widely separated formations ; so that CHAP . X. ] IN ANY SINGLE FORMATION . 71.
... fossils , though universally ranked as specifically different , yet are far more closely related to each other than are the species found in more widely separated formations ; so that CHAP . X. ] IN ANY SINGLE FORMATION . 71.
기타 출판본 - 모두 보기
자주 나오는 단어 및 구문
accumulated adapted admit affinity allied species ancient animals appear Archipelago arctic areas become believe birds breeds Cambrian changes characters classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo 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 mammæ mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation palæontologists paleozoic 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 species belonging stage stamens sterility structure successive suppose terrestrial tertiary tion variations varieties whilst widely different wings