mould.
Ten years after the publication of my paper, M. D Archiac, evidently
influenced by the doctrines of Elie de Beaumont, wrote about my
singuliere theorie, and objected that it could apply only to les
prairies basses et humides; and that les terres labourees, les bois,
les prairies elevees, n apportent aucune preuve a l appui de cette
maniere de voir. {4a} But M. D Archiac must have thus argued from inner
consciousness and not from observation, for worms abound to an
extraordinary degree in kitchen gardens where the soil is continually
worked, though in such loose soil they generally deposit their castings
in any open cavities or within their old burrows instead of on the
surface. Hensen estimates that there are about twice as many worms in
gardens as in corn-fields. {4b} With respect to prairies elevees, I do
not know how it may be in France, but nowhere in England have I seen the
ground so thickly covered with castings as on commons, at a height of
several hundred feet above the sea. In woods again, if the loose leaves
in autumn are removed, the whole surface will be found strewed with
castings. Dr. King, the superintendent of the Botanic Garden in
Calcutta, to whose kindness I am indebted for many observations on
earth-worms, informs me that he found, near Nancy in France, the bottom
of the State forests covered over many acres with a spongy layer,
composed of dead leaves and innumerable worm-castings. He there heard
the Professor of Amenagement des Forets lecturing to his pupils, and
pointing out this case as a beautiful example of the natural cultivation
of the soil; for year after year the thrown-up castings cover the dead
leaves; the result being a rich humus of great thickness.
In the year 1869, Mr. Fish {5} rejected my conclusions with respect to
the part which worms have played in the formation of vegetable mould,
merely on account of their assumed incapacity to do so much work. He
remarks that considering their weakness and their size, the work they
are represented to have accomplished is stupendous. Here we have an
instance of that inability to sum up the effects of a continually
recurrent cause, which has often retarded the progress of science, as
formerly in the case of geology, and more recently in that of the
principle of evolution.
Although these several objections seemed to me to have no weight, yet I
resolved to make more observations of the same kind as those published,
6