The Formation of Vegetable Mould, Through the Action of Worms: With Observations on Their HabitsD. Appleton, 1890 - 326 páginas |
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The formation of vegetable mould, through the action of worms, with Charles Darwin Vista completa - 1897 |
Términos y frases comunes
9 inches accumulated acetic acid acid action of worms alimentary canal amount angle animals annelids apex appear basal base Beaulieu Abbey beneath the surface blown broken brought buried burrows calciferous carbonic acid cent chalk concrete covered depth disintegration doubt dragged drawn earth feet field flints floor formed fragments fresh castings gizzards glands grass ground heavy rain Hensen holes hypocausts inches beneath inches deep inches in thickness inches thick inclined surface intestines Knole Park lamellæ land large number larvæ layer leaf leaves ledges Leith Hill Place lime Maer Hall manner matter mortar mouths nearly northern room objects observed particles pasture pavement penetrated Perrier petioles pharynx places ploughed plugging pots probably Roman villa rubbish sand seen seized side Silchester slope soil square yard Stonehenge stones subsided swallowed tesselated tiles tips trench triangles triturated turf upper vegetable mould walls washed weight whilst worm-castings
Pasajes populares
Página 310 - ... are before long all buried beneath the accumulated castings of worms, and are thus brought in a more or less decayed state within reach of the roots of plants. Worms likewise drag an infinite number of dead leaves and other parts of plants into their burrows, partly for the sake of plugging them up and partly as food. The leaves which are dragged into the burrows as food, after being torn into the finest shreds, partially digested, and saturated with the intestinal and urinary secretions, are...
Página 313 - The plough is one of the most ancient and most valuable of man's inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be ploughed, by earthworms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.
Página 143 - But the smaller stones disappeared before many years had elapsed, as did every one of the larger ones after a time ; so that after thirty years (1871) a horse could gallop over the compact turf from one end of the field to the other, and not strike a single stone with his shoes. To anyone who remembered the appearance of the field in 1842, the transformation was wonderful. This was certainly the work of the worms, for though castings were not frequent for several years, yet some were thrown up month...
Página 313 - When we behold a wide, turf-covered expanse, we should remember that its smoothness, on which so much of its beauty depends, is mainly due to all the inequalities having been slowly leveled by worms.
Página 305 - On each acre of land, he says, "in many parts of England, a weight of more than ten tons of dry earth annually passes through their bodies and is brought to the surface.
Página 305 - They have played a more important part in the history of the world than most persons would at first suppose.
Página 232 - Until the last twenty or thirty years, most geologists thought that the waves of the sea were the chief agents in the work of denudation; but we may now feel sure that air and rain, aided by streams and rivers, are much more powerful agents, - that is if we consider the whole area of the land.
Página 120 - ... deeper parts (supposing the whole to be equally moistened) from the greater weight of the superincumbent soil which has to be raised, than in the parts near the surface. When the ground dries, the walls will shrink a little and the burrows will be a little enlarged.
Página 113 - The piue-leaves had all been drawn in by their bases; and the sharp points of the needles had been pressed into the lining of voided earth. Had this not been effectually done, the sharp points would have prevented the retreat of the worms into their burrows ; and these structures would have resembled traps armed with converging points of wire, rendering the ingress of an animal easy and its egress difficult or impossible.