Worms are poorly provided with senseorgans, for they cannot be said to see, although they can just distinguish between light and darkness; they are completely deaf, and have only a feeble power of smell; the sense of touch alone is well developed. They can therefore learn little about the outside world, and it is surprising that they should exhibit some skill in lining their burrows with their castings and with leaves, and in the case of some species in piling up their castings into tower-like constructions. But it is far more surprising that they should apparently exhibit some degree of intelligence instead of a mere blind instinctive impulse, in their manner of plugging up the mouths of their burrows. They act in nearly the same manner as would a man, who had to close a cylindrical tube with different kinds of leaves, petioles, triangles of paper, &c., for they commonly seize such objects by their pointed ends. But with thin objects a certain number are drawn in by their broader ends. They do not act in the same unvarying manner in all cases, as do most of the lower animals; for instance, they do not drag in leaves by their foot-stalks, unless the basal part of the blade is as narrow as the apex. or narrower than it. 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 levelled by worms. It is a marvellous reflection that the whole of the superficial mould over any such expanse has passed, and will again pass, every few years through the bodies of worms. 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 thus ploughed by earth-worms. 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 organised creatures. Some other animals, however, stiil more lowly organised, namely corals, have done far more conspicuous work in having constructed innumerable reefs and islands in the great oceans; but these are almost confined to the tropical zones. INDEX. Abinger, Roman villa at, 178 castings from Roman villa, with rounded particles, 253 Acids of humus, action on rocks, 240 Africa, dust from, 235 Air, currents of, worms sensitive to, 28 Amount of earth brought to the surface by worms, 129 Ants. intelligence of, 93 Archiac, D', criticisms on my views, 4 Artemisia, leaves of, not eaten by worms, 33 Ash-tree, petioles of, 79 Beaulieu Abbey, burial of the old pavement, 193 255 Beaumont, Élie de, on vegetable mould, 2 178 the rubbish underlying great cities, the transport of dust, 237 the permanence of mould, 289 the permanence of ancient tumuli, 290 Beech-forests, stones not buried under by castings, 144 Bones, crushed, burial of, under castings, 146 Brading, Roman villa at, 199 Bridgman, Mr., on worms eating leaves of a Phlox, 33 Burrows, depth of, 109 direction of, on a slope, 270 excavation of, 98 lined with black earth, 111 lined with leaves, 112 mouths of, worms lie motionless near, 15 old, their collapse, 118 plugged up, 58 terminating in a small chamber, often lined with stones or seeds, 114 Calciferous glands, 17, 43 Cannibal worms, 36 - Carnagie, Mr., depth of burrows, 114 Castings, acid, 52 from Beaulieu, 101 tower-like, near Nice, 106 ejection of, 116 tower-like, from near Calcutta, 123 of great size on the Nilgiri Mountains, 126 thickness of layer formed from, during a year, 169 flowing down slopes, 261 washed away, 272 dry, disintegration of, 275 blown to leeward, 283 Cells, free, with calcareous matter in the calciferous glands, 47 Cellulose, digestion of, 37 |