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Show 128 HABITS OF WORMS. CIIAP. II. whilst soft, and that their diameters had thus been increased. Some had :flowed so much that they now consisted of a pile of almost flat confluent cal\:es. All were formed of fine, rather light-coloured earth, and were surprisingly hard and compact, owing no doubt to the animal rna tter by which the particles of earth had been cemented together. They did not disintegrate, even when left for some hours in water. Although they had been cast up on the surface of gravelly soil, they contained extremely few bits of rock, the lara-est of which was only ·15 inch in 5 diameter. Dr. King saw in Ceylon a worm about 2 feet in length and ! inch in diameter; and he was told that it was a very common species during the wet season. These worms must throw up castings at least as large as those on the Nilgiri Mountains; but Dr. King saw none during his short visit to Cey Ion. Sufficient facts have now been given, showing that worms do much work in bringing up fine earth to the surface in rnost or all parts of the world, and under the most different climates. ( 129 ) CHAPTER III. THE AMOUN'l' OF FINE EAR't'll BROUGHT UP BY WORMS TO TilE SURF ACE. Rate at which various objects stre\ved on the surface of grassfields are covered up by tho castings of worms-'l'he burial of a paved path-'rhe slow subsidence of great stones left on the surface-:-The number of worms which live within a given space-The weight of earth ejected from a burrow, and from all the burrows within a given space-Tho thickness of the layer of mould which tho castings on a given space would form within a given time if uniformly spreaJ out-The slow rate at which mould can increase to a great thicknessConclusion. WE now come to the more immediate subject of this volume, namely, the amount of earth which is brought up by worms from beneath the surface, and is afterwards spread out more or less completely by the rain and wind. The amount can be judged of by two methods,by the rate at which oqjects left on the surface are buried, and more accurately by weighing the quantity brought up within a K |