The origin of species by means of natural selectionРипол Классик, 1929 - 454 páginas |
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Página 3
... At the commencement of my observations it seemed to me probable that a careful study of domesticated animals and of cultivated plants would ofl'er the best chance of making out this obscure roblem. Nor have INTRODUCTION 3.
... At the commencement of my observations it seemed to me probable that a careful study of domesticated animals and of cultivated plants would ofl'er the best chance of making out this obscure roblem. Nor have INTRODUCTION 3.
Página 24
... observations, purposely made, on the most distinct breeds. Now, it is difficult, perha impossible, to bring forward one case of the ybri offspring of two animals clearly distinct being themselves perfectly fertile. Some authors believe ...
... observations, purposely made, on the most distinct breeds. Now, it is difficult, perha impossible, to bring forward one case of the ybri offspring of two animals clearly distinct being themselves perfectly fertile. Some authors believe ...
Página 47
... observations, he will meet with more cases of difficulty; for he will encounter a greater number of closely-allied forms. But if his observations be widely extended, he will in the end generally be enabled to make up his own mind which ...
... observations, he will meet with more cases of difficulty; for he will encounter a greater number of closely-allied forms. But if his observations be widely extended, he will in the end generally be enabled to make up his own mind which ...
Página 62
... observations which I have made, I believe that it is the seedlings which sufl'er most from germinating in ground already thickly stocked with other plants. Seedlings, also, are destroyed in vast numbers by various enemies; for instance ...
... observations which I have made, I believe that it is the seedlings which sufl'er most from germinating in ground already thickly stocked with other plants. Seedlings, also, are destroyed in vast numbers by various enemies; for instance ...
Página 67
... observed in parts 0 South America) the vegetation: this again would largely afl'ect the insects; and this, as we just have seen in Stafl'ordshire, the insectivorous birds, and so onwards in ever-increasing circles of complexity. We ...
... observed in parts 0 South America) the vegetation: this again would largely afl'ect the insects; and this, as we just have seen in Stafl'ordshire, the insectivorous birds, and so onwards in ever-increasing circles of complexity. We ...
Contenido
5 | |
ON was GEOLOGICAL SUCCESSION OF ORGANIC | 155 |
GEOGRAPHICAL DISTRIBUTION | 282 |
Gnoonnmcu DISTRIBUTION Continued | 302 |
RECAPITULATION AND CONCLUSION | 415 |
41 | 449 |
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Términos y frases comunes
action adapted advantage allied America amount ancient animals appear become believe birds breeds cause characters climate closely common considered continuous crossed descendants difl'erent distinct domestic doubt evidence existing extinct extremely facts families favourable fertility find first flowers follow formations forms genera genus give given greater groups habits hand Hence hybrids important increase individuals inhabitants inherited insects instance instincts intermediate islands kind known land laws less lines living look males manner means migration modification namely natural selection naturalists nearly never observed occur organic origin parent perfect period plants points present principle probably produced range ranked reason regions remains remarked resemble seeds seems seen separated shown single slight sometimes species sterility structure struggle successive suppose tend theory tion trees variability variations varieties vary whole widely