The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
Dentro del libro
Resultados 1-5 de 57
Página xviii
... observation des animaux sauvages démontre déjà la variabilité limitée des espèces . Les expériences sur les animaux sauvages devenus domestiques , et sur les animaux domestiques redevenus sauvages , la démontrent plus clairement encore ...
... observation des animaux sauvages démontre déjà la variabilité limitée des espèces . Les expériences sur les animaux sauvages devenus domestiques , et sur les animaux domestiques redevenus sauvages , la démontrent plus clairement encore ...
Página xxi
... many original observations . The first edition of this work was published on November 24th , 1859 , and the second edition on January 7th , 1860 . ORIGIN OF SPECIES . INTRODUCTION . WHEN on board H.M.S.. HISTORICAL SKETCH . xxi.
... many original observations . The first edition of this work was published on November 24th , 1859 , and the second edition on January 7th , 1860 . ORIGIN OF SPECIES . INTRODUCTION . WHEN on board H.M.S.. HISTORICAL SKETCH . xxi.
Página 3
... observations it seemed to me probable that a careful study of domesticated animals and of cultivated plants would offer the best chance of making out this obscure problem . Nor have I been disappointed ; in this and in all other ...
... observations it seemed to me probable that a careful study of domesticated animals and of cultivated plants would offer the best chance of making out this obscure problem . Nor have I been disappointed ; in this and in all other ...
Página 7
... observed with plants and animals when reared under new or unnatural con- ditions . Many facts clearly show how eminently susceptible the reproductive system is to very slight changes in the surrounding conditions . Nothing is more easy ...
... observed with plants and animals when reared under new or unnatural con- ditions . Many facts clearly show how eminently susceptible the reproductive system is to very slight changes in the surrounding conditions . Nothing is more easy ...
Página 17
... observed : -I crossed some white fantails , which breed very true , with some black barbs - and it so happens that blue varieties of barbs are so rare that I never heard of an instance in England ; and the mongrels were black , brown ...
... observed : -I crossed some white fantails , which breed very true , with some black barbs - and it so happens that blue varieties of barbs are so rare that I never heard of an instance in England ; and the mongrels were black , brown ...
Otras ediciones - Ver todas
Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young