The Variation of animals and plants under domestication v. 2, Volumul 2Appleton, 1876 |
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Pagina 3
... improved and valued breeds , such as the Southdowns . Since the time of the famous Bakewell , during the last century , the Leicester sheep have been bred with the most scrupulous care ; yet occasionally grey - faced , or black- spotted ...
... improved and valued breeds , such as the Southdowns . Since the time of the famous Bakewell , during the last century , the Leicester sheep have been bred with the most scrupulous care ; yet occasionally grey - faced , or black- spotted ...
Pagina 5
... improved breeds of the pigeon will not " field " or search for their own food . Sheep have never become feral , and would be destroyed by almost every beast of prey.10 In several cases we do not know the aboriginal parent - species ...
... improved breeds of the pigeon will not " field " or search for their own food . Sheep have never become feral , and would be destroyed by almost every beast of prey.10 In several cases we do not know the aboriginal parent - species ...
Pagina 37
... improving a breed , if care be taken for a length of time to exclude all inferior individuals , the breed will obviously tend to become truer , as it will not have been crossed during many generations by an inferior animal . We have ...
... improving a breed , if care be taken for a length of time to exclude all inferior individuals , the breed will obviously tend to become truer , as it will not have been crossed during many generations by an inferior animal . We have ...
Pagina 39
... improved breeds ; and as these latter are of modern origin , it has been thought that the greater antiquity of the wilder breeds has been the cause of their resistance to im- provement by crossing ; but it is more probably due to their ...
... improved breeds ; and as these latter are of modern origin , it has been thought that the greater antiquity of the wilder breeds has been the cause of their resistance to im- provement by crossing ; but it is more probably due to their ...
Pagina 41
... improved Short - horns , not- withstanding that the breed is comparatively modern , are generally acknowledged to possess great power in impressing their likeness on all other breeds ; and it is chiefly in consequence of this power that ...
... improved Short - horns , not- withstanding that the breed is comparatively modern , are generally acknowledged to possess great power in impressing their likeness on all other breeds ; and it is chiefly in consequence of this power that ...
Alte ediții - Afișează-le pe toate
The Variation of Animals and Plants Under Domestication V2 Professor Charles Darwin Nu există previzualizare disponibilă - 2014 |
The Variation of Animals and Plants Under Domestication V2 Charles Darwin Nu există previzualizare disponibilă - 2014 |
Termeni și expresii frecvente
analogous animals and plants Antirrhinum appear beak become birds bred breeders breeds buds cattle cause cells changed conditions chapter characters climate close interbreeding colour common correlation crossed degree diseases distinct species dogs domestic races domesticated animals doubt effects extremely facts Fancy Pigeons feathers female fertilised fertility flowers fowls Fritz Müller fruit Gard Gardener's Chronicle Gärtner gemmules given Hist horses hybrids improved individuals inherited insects instance Isidore Geoffroy Saint-Hilaire Journal kind Kölreuter large number larvæ liable maize male manner modified natural selection natural species nectarine niata observed occasionally offspring Oncidium flexuosum organs ovules pangenesis Paraguay parent parent-forms Parthenogenesis peculiar peloric period petals pigeons pigs pollen pollen-grains prepotent probably produced progenitor propagated quadrupeds racter remarks reproductive respect result reversion seed seedlings seen sexual sheep slight stamens sterility stripes structure tendency tion transmitted variability variations varieties various vary whilst wild yield Youatt
Pasaje populare
Pagina 488 - XVIII. The Nature of Light. With a General Account of Physical Optics. By Dr. Eugene Lommel. With 188 Illustrations and a Table of Spectra in Chromo-lithography.
Pagina 481 - ... publishers will spare no pains to include in the series the freshest investigations of the best scientific minds."— Boston Journal. " This series is admirably commenced by this little volume from the pen of Prof.
Pagina 481 - ... from giving a fuller account of these suggestive essays, only because we are sure that our readers will find it worth their while to peruse the book for themselves ; and we sincerely hope that the forthcoming parts of the 'International Scientific Series
Pagina 487 - ... science — the Chemistry of Light — and, in giving a popular view to the one, Dr. Vogel has presented an analysis of the principles and processes of the other. His treatise is as entertaining as it is instructive, pleasantly combining a history of the progress and practice of photography — from the first rough experiments of Wedgwood and Davy with sensitized paper, in 1802, down to the latest improvements of the art — with technical illustrations of the scientific theories on which the...
Pagina 412 - ... no shadow of reason can be assigned for the belief that variations, alike in nature and the result of the same general laws, which have been the ground-work through natural selection of the formation of the most perfectly adapted animals in the world, man included, were intentionally and specially guided. However much we may wish it, we can hardly follow Professor Asa Gray in his belief 'that variation has been led along certain beneficial lines, like a stream, along definite and useful lines...
Pagina 484 - ... but can be reduced to similar formula. The work is profusely illustrated, and, without reference to the theory it is designed to expound, will be regarded as a valuable addition to natural history.
Pagina 23 - As a general rule, crossed offspring in the first generation are nearly intermediate between their parents, but the grandchildren and succeeding generations continually revert, in a greater or lesser degree, to one or both of their progenitors.
Pagina 75 - Unless the characteristics and conformation of the two breeds are altogether averse to each other, nature opposes no barrier to their successful admixture ; so that, in the course of time, by the aid of selection and careful weeding, it is practicable to establish a new breed altogether.
Pagina 481 - The ' Forms of Water,' by Professor Tyndall, is an interesting and instructive little volume, admirably printed and illustrated. Prepared expressly for this series, it is in some measure a guarantee of the excellence of the volumes that will follow, and an indication that the publishers will spare no pains to include in the series the freshest investigations of the best scientific minds."—Boston Journal.
Pagina 483 - For, to those advanced students who have kept well abreast of the chemical tide, it offers a calm philosophy. To those others, youngest of the class, who have emerged from the schools since new methods have prevailed, it presents a generalization, drawing to its use all the data, the relations of which...