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 organized creatures. Some other animals, however, still
more lowly organized, 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.
FOOTNOTES.
{2} Lecons de Geologie Pratique, tom. i. 1845, p. 140.
{3} Transactions Geolog. Soc. vol. v. p. 505. Read November 1, 1837.
{4a} Histoire des progres de la Geologie, tom. i. 1847, p. 224.
{4b} Zeitschrift fur wissenschaft. Zoologie, B. xxviii. 1877, p. 361.
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