The American Journal of Science and ArtsS. Converse, 1860 |
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Página 21
... miles , I observe but one spot , namely , Eliza- beth Island , a mere speck of land , but which is the only known habitat of one of the most remarkable genera of Composite . 25. Many of the above facts in the general distribution of ...
... miles , I observe but one spot , namely , Eliza- beth Island , a mere speck of land , but which is the only known habitat of one of the most remarkable genera of Composite . 25. Many of the above facts in the general distribution of ...
Página 37
... miles . It is proposed specially to investigate the law of the eleven year period , or , as it is more frequently called , the decennial pe- riod , there being yet an uncertainty as to its precise length . It is supposed to have some ...
... miles . It is proposed specially to investigate the law of the eleven year period , or , as it is more frequently called , the decennial pe- riod , there being yet an uncertainty as to its precise length . It is supposed to have some ...
Página 43
... miles , in situations where they are available , yet it has appeared to me that the visual method I propose may prove use- ful in many cases where the stations to be compared , particularly the astronomical stations in a trigonometrical ...
... miles , in situations where they are available , yet it has appeared to me that the visual method I propose may prove use- ful in many cases where the stations to be compared , particularly the astronomical stations in a trigonometrical ...
Página 48
... miles , and next on the at- tainment of sufficient precision of rate in the uniform motion employed . I do not anticipate serious difficulty in either of these things . For the uniform motion , considering especially the light work it ...
... miles , and next on the at- tainment of sufficient precision of rate in the uniform motion employed . I do not anticipate serious difficulty in either of these things . For the uniform motion , considering especially the light work it ...
Página 82
... miles , or , if we include the Black Hills of Nebraska , 1,125 miles . " The great mountain mass , of which that in our territory forms but a part , extends with varying breadth nearly on the line of a great circle of the globe from ...
... miles , or , if we include the Black Hills of Nebraska , 1,125 miles . " The great mountain mass , of which that in our territory forms but a part , extends with varying breadth nearly on the line of a great circle of the globe from ...
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Términos y frases comunes
acid American ammonia animals antimony appears arsenic atomic weight aurora Australia beds bismuth carbon carbonic acid Carboniferous character chemical chlorid coast color containing Cretaceous crystals Dép described determine Dicotyledons direction dolomite equivalent existing fact flame flora fluorine formation formula fossil genera genus geographical geological gives gypsum horizon inches iridium iron Journal jurassic known lake less light lignite limestone magnetic mass matter metals meteor miles mineral mountains natural nearly northern observations obtained occur organic orthoclase osmium oxyd oxygen paper pectolite peculiar Permian phenomena phosphorus pieces plants plates platinum portion potash present Prof radials ratio relations remarkable river rocks ruthenium salt scientific SECOND SERIES Sept silica soda solution southern species specimens strata substance supposed surface temperature Tertiary theory tion upper variation varieties vegetation volume whole XXIX
Pasajes populares
Página 148 - 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.
Página 147 - 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...
Página 148 - I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number.
Página 158 - The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was small, budding twigs; and this connexion of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups.
Página 172 - When we travel southward and see a species decreasing in numbers, we may feel sure that the cause lies quite as much in other species being favored as in this one being hurt.
Página 170 - We behold the face of nature bright with gladness, we often see superabundance of food; we do not see, or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life ; or we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey...
Página 170 - 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.
Página 159 - ... extinct and living species in groups subordinate to groups. Of the many twigs which flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear the other branches ; so with the species which lived during long-past geological periods, very few have left living and modified descendants.
Página 449 - 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.
Página 158 - 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.