Comentarios de la gente - Escribir un comentario
No encontramos ningún comentario en los lugares habituales.
Otras ediciones - Ver todas
according animal appears arrangement become belonging body bright called carried century character close colour comet common considerable considered consists contains continued course covered described direction distance distinct doubt dress effect evidence examination exhibit existence experiments extremity fact feet feudal fish four give given greater head heat hydrogen important inches increase interesting kind known ladies length less light living looked marked mass material matter means mentioned metal minute month Moon nature nearly nebulæ noticed objects observed obtained occur organs passed period Plate portion position possess present probably produced remains remarkable represents resembling result round says seems seen separated short side similar species stars supposed surface taken temperature tube usually volume whole worms
Página 145 - The POLAR WORLD; a Popular Description of Man and Nature in the Arctic and Antarctic Regions of the Globe. By Dr.
Página 426 - For, to say nothing of half the birds, and some quadrupeds which are almost entirely supported by them, worms seem to be the great promoters of vegetation, which would proceed but lamely without them, by boring, perforating, and loosening the soil, and rendering it pervious to rains and the fibres of plants, by drawing straws and stalks of leaves and twigs into it ; and, most of all, by throwing up such infinite numbers of lumps of earth called worm-casts, which, being their excrement, is a fine...
Página 457 - HALF-HOURS WITH THE STARS: a Plain and Easy Guide to the Knowledge of the Constellations. Showing in 12 Maps the position oi the principal Star-Groups night after night throughout the year. With Introduction and a separate Explanation of each Map. True for every Year.
Página 425 - Earth-worms, though in appearance a small and despicable link in the chain of Nature, yet, if lost, would make a lamentable chasm. For, to say nothing of half the birds, and some quadrupeds, which are almost entirely supported by them, worms seem to be...
Página 427 - On carefully examining between the blades of grass in the fields above described, the author found that there was scarcely a space of two inches square without a little heap of the cylindrical castings of worms.
Página 427 - ... which cinders had been spread out only half a year before, Mr. Darwin actually saw the castings of the worms heaped on the smaller fragments. Nor is the agency so trivial as it at first might be thought, the great number of earth-worms (as every one must be aware who has ever dug in a grass field) making up for the insignificant quantity of work which each performs.
Página 166 - I cannot give you a more exact description of its figure than by comparing it to that of a pine-tree, for it shot up to a great height in the form of a trunk, which extended itself at the top into a sort of branches...
Página 266 - ... and the result of the same general laws, which have been the groundwork 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 of irrigation.
Página 144 - That the alloy contains about 20 volumes of palladium united with a volume of hydrogenium ; and that the density of the latter is about 2, a little higher than magnesium to which hydrogenium may be supposed to bear some analogy. That hydrogenium has a certain amount of tenacity, and possesses the electrical conductivity of a metal. And finally, that hydrogenium takes its place among magnetic metals. The latter fact may have its bearing upon the appearance of hydrogenium in meteoric iron, in association...
Página 74 - cold area " were to be raised above the surface, so that the deposit at present in progress upon its bottom should become the subject of examination by some Geologist of the future, he would find this to consist of a barren Sandstone, including fragments of older rocks, the scanty Fauna of which would in great degree bear a Boreal character (§ 11); whilst if a portion of our "warm area" were elevated at the same time with the