The Beginnings of Life: Being Some Account of the Nature, Modes of Origin & Transformation of Lower Organisms, Volumen2Appleton, 1872 |
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Términos y frases comunes
acid Actinophrys aggregate Algæ Amabæ ammonic tartrate Amoeba amoeboid amongst animal appearance assume Bacteria become blood bodies capable cells changes chlorophyll Ciliated Infusoria colloidal colour colourless complex contagious contained corpuscles crystalline crystals cyst decolourized Desmids diameter Diatoms diseases embryo encysted Euglena evolution existence fact fermentation filaments fission flagellum flask fluid forms Fungi fungus Fungus-germs germs globules gonidia gradually granular granules Gros heterogenetic increase influence infusion kind Leptothrix less Lichens living matter living things mass membrane ments microscopical minute mode of origin modes of growth modifications molecular molecules Monads motionless nature Nematoids novo observations occur ordinary organisms ovoid Oxytricha particles pellicle plants portions Pouchet present produced protoplasm reproduction Rotifers says seems seen segmentation similar solution species specimens spherical spores stages substance surface take place Tardigrades temperature tendency tion tissues Torula transformation turbidity undergo Vaucheria vegetal vesicles Vibriones Vorticella whilst zoospores
Pasajes populares
Página 600 - As all the living forms of life are the lineal descendants of those which lived long before the Cambrian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world.
Página 90 - We must infer that a plant or animal of any species, is made up of special units, in all of which there dwells the intrinsic aptitude to aggregate into the form of that species : just as in the atoms of a salt, there dwells the intrinsic aptitude to crystallize in a particular way.
Página 627 - ... his mental constitution may continue to advance and improve, till the world is again inhabited by a single nearly homogeneous race, no individual of which will be inferior to the noblest specimens of existing humanity.
Página 95 - ... other. The forces exercised by each unit on the aggregate, and by the aggregate on each unit, must ever tend towards a balance. If nothing prevents, the units will mould the aggregate into a form in equilibrium with their pre-existing polarities. If contrariwise, the aggregate is made by incident actions to take a new form, its forces must tend to re-mould the units into harmony with this new form ; and to. say that the physiological units are in any degree so...
Página 94 - ... and polarities of its units. The units and the aggregate must act and react on each other. The forces exercised by each unit on the aggregate and by the aggregate on each unit must ever tend towards a balance. If nothing prevents, the units will mould the aggregate into a form in equilibrium with their pre-existing polarities. If, contrariwise, the aggregate is made by incident actions to take a new form, its forces must tend to remould the units into harmony with this new form.
Página 98 - Throughout the process of evolution, the two kinds of units, mainly agreeing in their polarities and in the form which they tend to build themselves into, but having minor differences, work in unison to produce an organism of the species from which they were derived, but work in antagonism to produce copies of their respective parent-organisms. And hence ultimately results, an organism in which traits of the one are mixed with traits of the other.
Página 606 - The ordinary notion of species, as assemblages of individuals marked out from each other by definite characters that have been genetically transmitted from original prototypes similarly distinguished, is quite inapplicable to this group; since even if the limits of such assemblages were extended so as to include what would elsewhere be accounted genera, they would still be found so intimately connected by gradational links, that definite lines of demarcation could not be drawn between them.
Página 24 - ... suppose, that the chemical units combine into units immensely more complex than themselves, complex as they are ; and that in each organism, the physiological units produced by this further compounding of highly compound atoms, have a more or less distinctive character. We must conclude that in each case, some slight difference of composition in these units, leading to some slight difference in their mutual play of forces, produces a difference in the form which the aggregate of them assumes.
Página 450 - Brebisson states that a pond in the neighbourhood of Falain, having been rendered dry during many weeks in the height of summer, the ground was immediately and entirely covered, to the extent of many square yards, by a minute, compact green turf, formed of an...
Página 572 - I may be permitted to say, as some excuse, that I had two distinct objects in view : firstly, to show that species had not been separately created ; and, secondly, that natural selection had been the chief agent of change, though largely aided by the inherited effects of habit, and slightly by the direct action of the surrounding conditions.