The Formation of Vegetable Mould, Through the Action of Worms, with Observations on Their HabitsJ. Murray, 1883 - 328 páginas |
Otras ediciones - Ver todas
The Formation of Vegetable Mould, Through the Action of Worms, with ... Charles Darwin Vista previa limitada - 2015 |
The Formation of Vegetable Mould, Through the Action of Worms, with ... Charles Darwin Vista previa limitada - 2024 |
Términos y frases comunes
abound accumulated acetic acid acid action of worms alimentary canal amount angles animals annelids apex apical appears basal base Beaulieu Abbey beneath the surface bodies buried burrows calciferous cells cent chalk Claparède close concrete covered damp depth digestive disintegration doubt dragged drawn earth earth-worms ejected feet field flints floor fluid foot-stalk formed fragments garden gizzards glands gnawed grass ground Hensen hole inch in diameter inches beneath inches in thickness instinct intestines Knole Park lamellæ land large number larvæ layer leaf Leith Hill Place lime Maer Hall manner matter mortar mouths nearly needles night objects observed occasions oesophagus particles pasture pavement Perrier petioles pharynx pine-leaves places ploughed plugging pots probably Roman villa sand seen seized side Silchester slides of dark slope soil species Stonehenge stones subsided swallowed tesselated tiles tips trench triangles triturated turf upper vegetable mould walls washed weight whilst worm-castings worms
Pasajes populares
Página 298 - WORMS have played a more important part in the history of the world than most persons would at first suppose.
Página 306 - 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 306 - 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 224 - ... enough to give a proper knowledge of its weathering. He did however quote the estimate of a German chemist that disintegration of the granite surface would occur at the rate of 0-0085 to 0-0076 mm. annually. Charles Darwin, at one time a convinced marine erosionist, now admits his change of view: 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...
Página 55 - ... cold air could not enter the burrows, they plugged them up in a slovenly manner; and secondarily, because they often coat the upper part of their burrows with leaves, apparently to prevent their bodies from coming into close contact with the cold damp earth.
Página 298 - 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 20 - They were quite indifferent to my breath, as long as I breathed on them very gently. This was tried, because it appeared possible that they might thus be warned of the approach of an enemy. They exhibited the same indifference to my breath whilst I chewed some tobacco, and while a pellet of cotton-wool with a few drops of millefleurs perfume or of acetic acid was kept in my mouth.
Página 126 - Two other cases are worth recording. In the spring of 1835, a field, which had long existed as poor pasture and was so swampy that it trembled slightly when stamped on, was thickly covered with red sand so that the whole surface appeared at first bright red. When holes were dug in this field after an interval of about 2£ years, the sand formed a layer at a depth of f in.
Página 303 - ... nitrification. The bones of dead animals, the harder parts of insects, the shells of land-molluscs, leaves, twigs, etc., 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.
Página 58 - ... case the tips projected from the burrows ; and 26 had been seized near the middle, so that these had been drawn in transversely and were much crumpled. Therefore 80 per cent. (always using the nearest whole number) had been drawn in by the tip, 9 per cent. by the base or foot-stalk, and 11 per cent. transversely or by the middle. This alone is almost sufficient to show that chance does not determine the manner in which leaves are dragged into the burrows.