The Geological History of PlantsD. Appleton & Company, 1892 - 294 pagini |
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Pagina 10
... seems to mark the stratification of the rock . " He further states : " The plumbago is not confined to the lime- stones ; large crystalline scales of it are occasionally dis- seminated in pyroxene rock , and sometimes in quartzite and ...
... seems to mark the stratification of the rock . " He further states : " The plumbago is not confined to the lime- stones ; large crystalline scales of it are occasionally dis- seminated in pyroxene rock , and sometimes in quartzite and ...
Pagina 13
... seems probable that the numerous reticulating veins of graphite may have been formed by the segregation of bituminous matter into fissures and planes of least resistance , in the manner in which such veins occur in modern bituminous ...
... seems probable that the numerous reticulating veins of graphite may have been formed by the segregation of bituminous matter into fissures and planes of least resistance , in the manner in which such veins occur in modern bituminous ...
Pagina 18
... seems to have been introduced in the full pleni- tude of its powers in the Laurentian age . Whether this early Laurentian vegetation was the means of sustaining any animal life other than marine Protozoa , we do not know . It may have ...
... seems to have been introduced in the full pleni- tude of its powers in the Laurentian age . Whether this early Laurentian vegetation was the means of sustaining any animal life other than marine Protozoa , we do not know . It may have ...
Pagina 19
... seems rather in excess of the demand , and it may well be that there are uses of graphite still undiscovered , and to which it will yet be applied . Finally , it is deserving of notice that , if Laurentian graphite indicates vegetable ...
... seems rather in excess of the demand , and it may well be that there are uses of graphite still undiscovered , and to which it will yet be applied . Finally , it is deserving of notice that , if Laurentian graphite indicates vegetable ...
Pagina 20
... seem rather to be grooves or marks cut in clay by the limbs or tails of some aquatic animal , and afterwards filled up and preserved by succeeding deposits . After examining large series of these specimens from Sweden , and from rocks ...
... seem rather to be grooves or marks cut in clay by the limbs or tails of some aquatic animal , and afterwards filled up and preserved by succeeding deposits . After examining large series of these specimens from Sweden , and from rocks ...
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Termeni și expresii frecvente
abundant Acrogens aërial roots Algæ allied America animal appear arctic areoles bark beds belong bituminous branches Brongniart Calamites Canada carbon Carboniferous Caulopteris cellular character clay climate coal coal-formation conifers Cordaites cycads Dadoxylon Dawson deposits described Devonian diameter dicotyledonous Eocene Europe exogenous fact ferns flora formation forms fossil fossil plants fronds fructification fruit Gaspé genera genus Geological Society graphite Greenland gymnospermous Heer hemisphere Journal known land land-plants Laramie Laurentian leaf-bases leaf-scars leaves Lepidodendron Lepidophloios Lesquereux limestone Lower Carboniferous Lycopods macrospores matter medullary rays Mesozoic Miocene modern Nematophyton northern Nova Scotia occur outer Palæozoic period Permian pines pinnules pith present preserved probably Prof Psilophyton referred remarkable resemble Rhizocarps rocks sandstones scalariform scars Sequoia shales Sigillaria Silurian similar species specimens Sphenophyllum Sporangites spore-cases spores sporocarps stems Sternbergia structure surface Tertiary thick tion tissue tree-ferns trees trunks types Upper Cretaceous vascular vegetable wood woody