The Shipley Collection of Scientific Papers, Nide 271891 |
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Abart Ahnenplasmen Algen Amphimixis andere antheridium apocytial archegonium Arten Ascaris Bedeutung Befruchtung beiden blastomeres blastophore Carapace cavity cell characters chromatin cocoons colour Combinationen Conjugation cytoplasm divisions Doppelte Eier Eiern Einzelligen Eizelle embryos enthalten Entwicklung erste ersten fission fissure formation Fortpflanzung gametes gametogonium gelben Zellen Generationen germ gleich Grunde habe Hälfte Hertwig heute Idanten Idioplasma individuals Individuen Individuums Infusorien isogamy jetzt karyogamy Keim Keimplasma Keimzellen Kern Kernstäbchen Kernsubstanz können könnte larvæ Leben Masse Maupas Metazoa Metazoen Micronucleus möchte möglich muss müssen nebenkerne nuclear nucleus observed oogonium oosphere organism ovum pancreas parasites Parthenogenese parthenogenetische plasma plasmosomata polar bodies pronuclei protoplasm Reductionstheilung rejuvenescence richtig Richtungskörper scheint schon Sinne spermatogonium spermatozoa Stäbchen stage staining substance Thatsache Theil Theilung Theilungen Thiere Thieren tion überhaupt variations Verdoppelung Vermehrung verschiedene viel vielleicht vier Vorgang Vortheil Weise Weismann wieder wohl würde Zahl Zeit Zelle zoospores zusammen zwei zweier zygote zymogen zymogen granules
Suositut otteet
Sivu 81 - Illustrated Encyclopaedic Medical Dictionary : Being a Dictionary of the Technical Terms used by Writers on Medicine and the Collateral Sciences in the Latin, English, French, and German Languages.
Sivu 20 - It follows as an unprejudiced conclusion from our present evidence that upon Weismann's principle we can explain inheritance but not evolution, while with Lamarck's principle and Darwin's selection principle we can explain evolution, but not, at present, inheritance. Disprove Lamarck's principle and we must assume that there is some third factor in evolution of which we are now ignorant.
Sivu 10 - I have hitherto sometimes spoken as if the variations — so common and multiform with organic beings under domestication, and in a lesser degree with those under nature — were due to chance. This, of course is a wholly incorrect expression, but it serves to acknowledge plainly our ignorance of the cause of each particular variation.
Sivu 1 - ... it seems to me that I enunciate a proposition which constitutes the very pith and marrow of the first edition of the " Origin of Species. " And what the evolutionist stands in need of just now, is not an iteration of the fundamental principle of Darwinism, but some light upon the questions, What are the limits of variation ? and, If a variety has arisen, can that variety be perpetuated, or even intensified, when selective conditions are indifferent, or perhaps unfavourable, to its existence?
Sivu 66 - May it not then be possible that the sexuality of the higher Fungi has disappeared because its purpose has been equally well, or better attained otherwise than by means of sexual organs ? The two points common to all cases of sexual reproduction are : — i.
Sivu 10 - Natural selection remains still a vera causa in the origin of species; but the function ascribed to it is practically reversed. It exchanges its former supremacy as the supposed sole determinant among practically indefinite possibilities of structure and function, for the more modest position of simply accelerating, retarding or terminating the process of otherwise determined change.