The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1898 |
Dentro del libro
Resultados 1-5 de 54
Página 18
... belonging to quite distinct families ; and , on the other hand , closely allied species , and varieties of the same species , can usually , but not invariably , be grafted with ease . But this capacity , as in hybridisation , is by no ...
... belonging to quite distinct families ; and , on the other hand , closely allied species , and varieties of the same species , can usually , but not invariably , be grafted with ease . But this capacity , as in hybridisation , is by no ...
Página 22
... belonging to a so- cial community , if rendered slightly sterile when crossed with some other variety , would not thus itself gain any advantage or indirectly give any advantage to the other individuals of the same variety , thus ...
... belonging to a so- cial community , if rendered slightly sterile when crossed with some other variety , would not thus itself gain any advantage or indirectly give any advantage to the other individuals of the same variety , thus ...
Página 29
... belonging to distinct orders present two forms , which exist in about equal numbers and which differ in no respect except in their reproductive organs ; one form having a long pistil with short stamens , the other a short pistil with ...
... belonging to distinct orders present two forms , which exist in about equal numbers and which differ in no respect except in their reproductive organs ; one form having a long pistil with short stamens , the other a short pistil with ...
Página 59
... belonging to either of these vast periods , with the exception of one species discovered by Sir C. Lyell and Dr. Dawson in the carboniferous strata of North America ; but now land - shells have been found in the lias . In regard to ...
... belonging to either of these vast periods , with the exception of one species discovered by Sir C. Lyell and Dr. Dawson in the carboniferous strata of North America ; but now land - shells have been found in the lias . In regard to ...
Página 60
... belonging to the age of our secondary or palæo- zoic formations . But the imperfection in the geological record largely results from another and more important cause than any of the foregoing ; namely , from the several forma- tions ...
... belonging to the age of our secondary or palæo- zoic formations . But the imperfection in the geological record largely results from another and more important cause than any of the foregoing ; namely , from the several forma- tions ...
Otras ediciones - Ver todas
Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe belonging birds Cambrian changes characters cies classification climate closely allied 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 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 palæontologists Palæozoic 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 stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst whole widely different wings