The American Journal of Science and ArtsS. Converse, 1860 |
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Стр. 5
... facts derived from a study of classification ; secondly , from distribution ; thirdly , from fossils ; after which I shall ex- amine the theories with which these facts should harmonize . §2 . On the General Phenomena of Variation in ...
... facts derived from a study of classification ; secondly , from distribution ; thirdly , from fossils ; after which I shall ex- amine the theories with which these facts should harmonize . §2 . On the General Phenomena of Variation in ...
Стр. 7
... fact is , that this element of mutability pervades the whole vegetable kingdom ; no class nor order nor genus of more than a few species claims absolute exemption , whilst the grand total of unstable forms generally assumed to be ...
... fact is , that this element of mutability pervades the whole vegetable kingdom ; no class nor order nor genus of more than a few species claims absolute exemption , whilst the grand total of unstable forms generally assumed to be ...
Стр. 12
... fact that the plant is found to be provided with the means of availing itself of them when provided , while at the same time it retains all its functions , not only unimpaired , but in many cases in a more highly developed state . We ...
... fact that the plant is found to be provided with the means of availing itself of them when provided , while at the same time it retains all its functions , not only unimpaired , but in many cases in a more highly developed state . We ...
Стр. 14
... fact that there are limits to these mutations , and laws that control the changes both as to degree and kind ; that species are neither visionary nor even arbitrary creations of the naturalist ; that they are , in short , realities ...
... fact that there are limits to these mutations , and laws that control the changes both as to degree and kind ; that species are neither visionary nor even arbitrary creations of the naturalist ; that they are , in short , realities ...
Стр. 15
... fact that in all isolated areas the number of classes , orders , and genera is very large in proportion to that of species . 83. On the General Phenomena of Distribution in Area . Turning now to another class of facts , those that refer ...
... fact that in all isolated areas the number of classes , orders , and genera is very large in proportion to that of species . 83. On the General Phenomena of Distribution in Area . Turning now to another class of facts , those that refer ...
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Часто встречающиеся слова и выражения
acid Alethopteris American animals antimony appears arsenic atomic atomic weight aurora axis ball bismuth Brgt bright carbon carbonic acid Carboniferous character chemical clouds coal coast color containing Cretaceous crystals described determined diameter Dicotyledons direction east existence extended fact feet flame flora fossil genera genus geological give Gulf Stream heat horizon inches Jour Journal Lake Lepidodendron less light limestone Lsqx mass matter means metals meteor miles mineral motion mountains natural nearly nebular hypothesis Neuropteris northern observations obtained organic origin osmium oxyd oxygen Pecopteris peculiar phenomena plants plates platinum portion potash present produced Prof relations remarkable river rocks ruthenium sandstone scientific SECOND SERIES seen Sept shales species specimens Sphenopteris strata stream streamers substance supposed surface temperature theory thickness tion variation varieties vegetation velocity whole zenith
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Стр. 172 - I cannot doubt that the theory of descent with modification embraces all the members of the same great class or kingdom. I believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number.
Стр. 144 - As all the living forms of life are the lineal descendants of those which lived long before the Cambrian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world. Hence we may look with some confidence to a secure future of great length. And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.
Стр. 143 - Judging from the past, we may safely infer that not one living species will transmit its unaltered likeness to a distant futurity. And of the species now living very few will transmit progeny of any kind to a far distant futurity...
Стр. 154 - The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was...
Стр. 166 - There is no exception to the rule that every organic being naturally increases at so high a rate that, if not destroyed, the earth would soon be covered by the progeny of a single pair.
Стр. 166 - 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.
Стр. 170 - But if variations useful to any organic being ever do occur, assuredly individuals thus characterised will have the best chance of being preserved in the struggle for life ; and from the strong principle of inheritance, these will tend to produce offspring similarly characterised. This principle of preservation, or the survival of the fittest, I have called Natural Selection.
Стр. 155 - ... in a fossil state. As we here and there see a thin straggling branch springing from a fork low down in a tree...
Стр. 445 - THE BOYDEN PREMIUM URIAH A. BOYDEN, ESQ., of Boston, Mass., has deposited with THE FRANKLIN INSTITUTE the sum of one thousand dollars, to be awarded as a premium to "Any resident of North America who shall determine by experiment whether all rays of light,* and other physical rays, are or are not transmitted with the same velocity.
Стр. 154 - The green and budding twigs may represent existing species ; and those produced during former years may represent the long succession of extinct species. At each period of growth all the growing twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same manner as species and groups of species have at all times overmastered other species in the great battle for life.