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acquired action acts adapted already seen Amoeba amongst amphibian ancestors ancient appears aquatic beauty become believe birds bones buds changes CHAPTER characters complex considerable correlated Crustacea Darwin deposits descendants direct embryo energy evidence evidence of evolution evolution excreted existence external extinct extremely facts favour fish Foraminifera formation fossils gemmules genera give rise gradually hence highly developed Hipparion hypothesis increase individual influence inheritance lancelet large number laws less light living lower forms Macrauchenia mammalia mammals material matter maturity modification natural selection nerve-cells nitrogen nodal lines nourishment nutrition occur offspring organs Origin of Species ovum Pangenesis parent patagium penguins period phenomena plasticity Plate probably produce protoplasm pseudopodia race relation reproduction reptiles reptilian result rudimentary Sirenia skull specialized sternum strata structure structureless suppose survival tendency tertiary theory tion tissue transitional forms undergo undoubtedly variability variation vary vast number vertebrates vibrations volition whilst wings young
Página 136 - I look at the geological record as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved ; and of each page, only here and there a few lines.
Página 120 - Whilst at work I seemed to myself to have been endeavouring to decipher a palimpsest, and one not erased and written upon again just once, but five or six times over. " Having erased, as it were, the characters of the culminating type — those of the gaudy Indian bird — I seemed to be amongst the sombre grouse ; and then, towards incubation, the characters of the sand-grouse and hemipod stood out before me. Rubbing these away, in my downward work the form of the tinamou looked me in the face ;...
Página 148 - ... yet it is not improbable that there is a certain amount of interference between the development of free intelligence and of instinct — which latter implies some inherited modification of the brain. Little is known about the functions of the brain, but we can perceive that as the intellectual powers become highly developed, the various parts of the brain must be connected by very intricate channels of the freest intercommunication; and as a consequence, each separate part would perhaps tend...
Página 109 - As natural selection acts solely by the preservation of profitable modifications, each new form will tend in a fully-stocked country to take the place of, and finally to exterminate, its own less improved parent-form and other less-favoured forms with which it comes into competition.
Página 140 - At some future period, not very distant as measured by centuries, the civilized races of man will almost certainly exterminate and replace throughout the world the savage races.
Página 49 - If strange and rare deviations of structure are really inherited, less strange and commoner deviations may be freely admitted to be inheritable. Perhaps the correct way of viewing the whole subject would be, to look at the inheritance of every character whatever as the rule, and non-inheritance as the anomaly.
Página 33 - Several writers have misapprehended or objected to the term Natural Selection. Some have even imagined that natural selection induces variability, whereas it implies only the preservation of such variations as arise and are beneficial to the being under its conditions of life.