On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
Dentro del libro
Resultados 1-5 de 79
Página 5
... known laws of variation and of correlation of growth . In the four succeeding chapters , the most apparent and gravest difficulties on the theory will be given namely , first , the difficulties of transi- tions , or in understanding how ...
... known laws of variation and of correlation of growth . In the four succeeding chapters , the most apparent and gravest difficulties on the theory will be given namely , first , the difficulties of transi- tions , or in understanding how ...
Página 13
... known to appear at the corresponding caterpillar or cocoon stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and that when there is no apparent reason why a peculiarity should ...
... known to appear at the corresponding caterpillar or cocoon stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and that when there is no apparent reason why a peculiarity should ...
Página 22
... known ; and these have not any of the characters of the domestic breeds . Hence the supposed aboriginal stocks must either still exist in the countries where they were originally domesticated , and yet be unknown to ornithologists ; and ...
... known ; and these have not any of the characters of the domestic breeds . Hence the supposed aboriginal stocks must either still exist in the countries where they were originally domesticated , and yet be unknown to ornithologists ; and ...
Página 23
... - bar , and barred and white - edged tail - feathers , as any wild rock - pigeon ! We can understand these facts , on the well - known principle of reversion to ancestral characters , if all the domestic VARIATION UNDER DOMESTICATION 23.
... - bar , and barred and white - edged tail - feathers , as any wild rock - pigeon ! We can understand these facts , on the well - known principle of reversion to ancestral characters , if all the domestic VARIATION UNDER DOMESTICATION 23.
Página 25
... the world ; the earliest known record of pigeons is in the fifth Egyptian dynasty , about 3000 B.o. , as was pointed out to me by Professor " Lepsius ; but Mr. Birch informs me that pigeons VARIATION UNDER DOMESTICATION 25.
... the world ; the earliest known record of pigeons is in the fifth Egyptian dynasty , about 3000 B.o. , as was pointed out to me by Professor " Lepsius ; but Mr. Birch informs me that pigeons VARIATION UNDER DOMESTICATION 25.
Otras ediciones - Ver todas
Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely