Darwinism and Human LifeHolt, 1917 - 263 pages |
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Page viii
... Germinal Selection - Variational Stimuli - Modifications or Acquired Charac- ters - Indirect Importance of Modifications - Modification - Species- Individual Plasticity - Relation to Human Life · pp . 97-120 CHAPTER V FACTS OF ...
... Germinal Selection - Variational Stimuli - Modifications or Acquired Charac- ters - Indirect Importance of Modifications - Modification - Species- Individual Plasticity - Relation to Human Life · pp . 97-120 CHAPTER V FACTS OF ...
Page 97
... Germinal ORGANIC PROGRESS PRIMARILY DEPENDS ON VARIABILITY . - The most difficult problem in bio- logy - part of the persisting mystery of life itself— is the innate changefulness which we often see manifested in a family , a herd , or ...
... Germinal ORGANIC PROGRESS PRIMARILY DEPENDS ON VARIABILITY . - The most difficult problem in bio- logy - part of the persisting mystery of life itself— is the innate changefulness which we often see manifested in a family , a herd , or ...
Page 112
... germinal variations comes from the oscillations and changes in the immediate surroundings of the germ - cells . They get their food- supply from the body , and that food - supply is liable to be somewhat variable . It may contain a ...
... germinal variations comes from the oscillations and changes in the immediate surroundings of the germ - cells . They get their food- supply from the body , and that food - supply is liable to be somewhat variable . It may contain a ...
Page 113
... GERMINAL SELECTION . - In his theory of " ger- minal selection " Weismann elaborated a very interesting speculation in regard to the roots of variation . With his characteristic way of following an idea as far as it would lead him , he ...
... GERMINAL SELECTION . - In his theory of " ger- minal selection " Weismann elaborated a very interesting speculation in regard to the roots of variation . With his characteristic way of following an idea as far as it would lead him , he ...
Page 114
... germinal selection supplies the stones out of which personal selection builds her temples and palaces : adapta- tions . " 1 The theory is , of course , entirely hypothetical , dealing as it does with the invisible , but it enables us to ...
... germinal selection supplies the stones out of which personal selection builds her temples and palaces : adapta- tions . " 1 The theory is , of course , entirely hypothetical , dealing as it does with the invisible , but it enables us to ...
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Common terms and phrases
acquired characters adaptations Alfred Russel Wallace animals Arthur Thomson become biological birds blue body breed called cells Charles Darwin chromosomes colour continuity correlation Darwin's day Darwinian direction discriminate elimination disease dominant dysgenic egg-cell endeavour environment eugenic evidence fact factors favour female fertilised forms formula Galton gametes germ-cells germinal variations hereditary heredity heritable human society idea illustration important individual influence inheritance insects instance interpretation Karl Pearson kind large number larvæ living creatures London male mating mean Mendelian MENDELIAN INHERITANCE mice modifica modifications mutations natural selection naturalists normal nurture nutritive chains offspring organic evolution Origin of Species ovum owe to Darwin parents peculiarities plants Prof progress PURPLE CLOVER qualities question race raw material Ray Lankester realise recognise regard result says scientific mood sifting spermatozoon struggle for existence suggested survival theory of natural things tion transmission variability Wallace
Popular passages
Page 69 - Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult — at least I have found it so — than constantly to bear this conclusion in mind. Yet unless it be thoroughly engrained in the mind, the whole economy of nature, with every fact on distribution, rarity, abundance, extinction, and variation, will be dimly seen or quite misunderstood.
Page 182 - I happened to read for amusement ' Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances • favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of a new species. Here, then, I had at last got a theory by which to work...
Page 36 - Therefore, my success as a man of science, whatever this may have amounted to, has been determined, as far as I can judge, by complex and diversified mental qualities and conditions. Of these, the most important have been — the love of science — unbounded patience in long reflecting over any subject — industry in observing and collecting facts — and a fair share of invention as well as of common-sense. With such moderate abilities as I possess, it is truly surprising that I should have influenced...
Page 70 - Within himself, from more to more; Or, crown'd with attributes of woe Like glories, move his course, and show That life is not as idle ore, But iron dug from central gloom, And heated hot with burning fears, And dipt in baths of hissing tears, And batter'd with the shocks of doom To shape and use.
Page 238 - And the eye cannot say unto the hand, I have no need of thee : nor again the head to the feet, I have no need of you.
Page 58 - It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.
Page 53 - Newman, who has long attended to the habits of humble-bees, believes that "more than two-thirds of them are thus destroyed all over England.
Page 11 - ... greatly alter (as indeed I have observed in parts of South America) the vegetation: this again would largely affect the insects ; and this, as we...
Page 34 - I had, also, during many years followed a golden rule, namely, that whenever a published fact, a new observation or thought came across me, which was opposed to my general results, to make a memorandum of it without fail and at once; for I had found by 69 experience that such facts and thoughts were far more apt to escape from the memory than favourable ones.
Page 142 - It must be clearly understood that there is nothing in these statements to invalidate the general doctrine that the children of a gifted pair are much more likely to be gifted than the children of a mediocre pair. They merely express the fact that the ablest of all the children of a few gifted pairs is not likely to be as gifted as the ablest of all the children of a very great many mediocre pairs