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BRITISH ANNELIDS.
Let me first claim the reader's indulgence for a moment while I
attempt a brief description of the class of animals to which the
earthworm belongs. If we admit that every member of the animal
kingdom must belong either to the vertebrates or the invertebrates
—just as every plant must be a phanerogam or a cryptogam—then we
know that worms are invertebrates, because they are boneless. Now
the invertebrate animals fall into a number of sub-kingdoms, the
names of which I need not detail. One of these divisions, however,
must include worms, and to it the name of Annulosa, or Articulata,
is applied. The latter term, invented by Cuvier to represent
this sub-kingdom of animate nature, is now usually replaced by
the former ; and the Annulose or articulated animals are again
subdivided into smaller groups. One of these bears the name
of Annelids, the members of which are normally distinguished
by the possession of a jointed body and a double nerve-chain on the
ventral or under surface of the body. In addition to the earth-
worms, there are also included in this class the leeches and freshwater
worms on the one hand, and the marine worms on the other.
Not one of these groups is well known. There are numerous
freshwater worms in our streams and stagnant waters whose life-
history has never been carefully worked out by any British naturalist
trained in the new school of biology, while the distribution of the
leeches is almost unknown. Some attention has been given of late
years by the marine biologist, to the curious and surpassingly
interesting annelids found on our shores, but the results of their
researches are not in the hands of the public. Under these circum-
stances it seems eminently desirable that something should be done
to put us on a level with our continental and American fellow-
workers in this department of science.
While I shall hope eventually to deal with each of the groups
included among the annelids, it will be necessary for the present to
confine attention entirely to that group which is at once the most
widely distributed and the most easily worked—the Earthworms or
Oligochaetes. This group of animals may be described as pre-
eminently domestic. By this I mean, that, wherever man is found,
there will the worms be also ; whereas they are almost entirely absent
from our broad moorlands and bleak mountains, except where the
cattle graze, and the collie seeks up the sheep. Their distribution is
very wide. The following hints will afford the collector all the
information he needs for starting him in his pursuit, experience