The Doctrine of Descent and DarwinismD. Appleton, 1875 - 334 من الصفحات |
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الصفحة 35
... genera , and tufts of species , which latter ramify into sub - species and varieties . With this representation of the tree - like distribution of the system , we shall gladly revert to the comparison of the members of different types ...
... genera , and tufts of species , which latter ramify into sub - species and varieties . With this representation of the tree - like distribution of the system , we shall gladly revert to the comparison of the members of different types ...
الصفحة 42
... genera of coral depends merely on minor modifications of this mode of reproduction . Yet single corals exist in which , on careful comparison , not only may accidental deviations be already discerned , but regularly recurring variations ...
... genera of coral depends merely on minor modifications of this mode of reproduction . Yet single corals exist in which , on careful comparison , not only may accidental deviations be already discerned , but regularly recurring variations ...
الصفحة 46
... genera- tion arise cell - spheres , or germs , which develope into the second generation - the Cercaria . Great excitement was likewise aroused by the dis- DEVELOPMENT OF UNFERTILIZED OVA . 47 covery of the germ 46 THE DOCTRINE OF DESCENT .
... genera- tion arise cell - spheres , or germs , which develope into the second generation - the Cercaria . Great excitement was likewise aroused by the dis- DEVELOPMENT OF UNFERTILIZED OVA . 47 covery of the germ 46 THE DOCTRINE OF DESCENT .
الصفحة 57
... genera , which , by all systematic rules , and by their geological position , occupy a lower rank in the series of echino- derms . The crabs , or anourous crustacea , are raised by sundry characteristics above their long - tailed ...
... genera , which , by all systematic rules , and by their geological position , occupy a lower rank in the series of echino- derms . The crabs , or anourous crustacea , are raised by sundry characteristics above their long - tailed ...
الصفحة 77
... genera and species distinguished from one another by mere shades , so that of two allied genera it is often difficult , nay , impossible , to state which.
... genera and species distinguished from one another by mere shades , so that of two allied genera it is often difficult , nay , impossible , to state which.
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عبارات ومصطلحات مألوفة
according adaptation already Ammonites Amphibians animal world apes appearance Ascidian become birds brain causes Cetacea character characteristics comparative anatomy complete connection continent Darwin dentition derivation diverge doctrine of Descent Echinoderms embryonic Eocene exhibit external facts families fauna fish formation fossil Ganoids Gastrula genera genus geological Goethe grade gradually groups Haeckel heredity higher horse human hypothesis idea individual infer intermediate forms islands lancelet language larva larvæ likewise linguistic Linnæus lower mammals Marsupials Medusa ment merely metamorphosis modifications morphological mutability natural selection observation Oolite organisms origin peculiar pedigree perfect period phase phenomena placenta plants polypes possess present primordial progenitors races relations remains reproduction reptiles resemblance Rütimeyer says scarcely scientific separate sexual Silurian skull species sponges strata structure systematic terrestrial animals Tertiary theory of selection tion transformation transition true Ungulata Ungulates varieties vegetal vertebral column Vertebrata vertebrate animals whole
مقاطع مشهورة
الصفحة 162 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.18 Darwin always knew that his views would be controversial. A few days before The Origin of Species appeared, Darwin wrote, in a letter to Wallace, 'God knows what...
الصفحة 160 - I had not formerly sufficiently considered the existence of many structures which appear to be, as far as we can judge, neither beneficial nor injurious ; and this I believe to be one of the greatest oversights as yet detected in my work.
الصفحة 160 - Na'geli on plants, and the remarks by various authors with respect to animals, more especially those recently made by Professor Broca, that in the earlier editions of my Origin of Species I perhaps attributed too much to the action of natural selection or the survival of the fittest.