The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 - 432 páginas |
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Página 245
... crustaceans ( al- lied to Penceus ) first appear under the simple nauplius- form , and after passing through two or more zoea - stages , and then through the mysis - stage , finally acquire their mature structure : now in the whole ...
... crustaceans ( al- lied to Penceus ) first appear under the simple nauplius- form , and after passing through two or more zoea - stages , and then through the mysis - stage , finally acquire their mature structure : now in the whole ...
Página 250
... crustaceans , spiders , and some members of the great class of insects . With respect to the final cause of the young in such groups not passing through any metamorphosis , we can see that this would follow from the following ...
... crustaceans , spiders , and some members of the great class of insects . With respect to the final cause of the young in such groups not passing through any metamorphosis , we can see that this would follow from the following ...
Página 252
... Crustacea , forms wonderfully distinct from each other , namely , suctorial parasites , cirripedes , entomo- straca , and even the malacostraca , appear at first as larvæ under the nauplius - form ; and as these larvæ live and feed in ...
... Crustacea , forms wonderfully distinct from each other , namely , suctorial parasites , cirripedes , entomo- straca , and even the malacostraca , appear at first as larvæ under the nauplius - form ; and as these larvæ live and feed in ...
Página 254
... crustaceans . As the embryo often shows us more or less plainly the structure of the less modi- fied and ancient progenitor of the group , we can see why ancient and extinct forms so often resemble in their adult state the embryos of ...
... crustaceans . As the embryo often shows us more or less plainly the structure of the less modi- fied and ancient progenitor of the group , we can see why ancient and extinct forms so often resemble in their adult state the embryos of ...
Página 308
... Crustaceans and Centipedes ) . ASYMMETRICAL . - Having the two sides unlike . ATROPHIED . - Arrested in development at a very early stage . BALANUS . The genus including the common Acorn - shells which live in abundance on the rocks of ...
... Crustaceans and Centipedes ) . ASYMMETRICAL . - Having the two sides unlike . ATROPHIED . - Arrested in development at a very early stage . BALANUS . The genus including the common Acorn - shells which live in abundance on the rocks of ...
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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