Nature of the sites inhabited--Can live long under water--
Nocturnal--Wander about at night--Often lie close to the mouths of
their burrows, and are thus destroyed in large numbers by birds--
Structure--Do not possess eyes, but can distinguish between light
and darkness--Retreat rapidly when brightly illuminated, not by a
reflex action--Power of attention--Sensitive to heat and cold--
Completely deaf--Sensitive to vibrations and to touch--Feeble power
of smell--Taste--Mental qualities--Nature of food--Omnivorous--
Digestion--Leaves before being swallowed, moistened with a fluid of
the nature of the pancreatic secretion--Extra-stomachal digestion--
Calciferous glands, structure of--Calcareous concretions formed in
the anterior pair of glands--The calcareous matter primarily an
excretion, but secondarily serves to neutralise the acids generated
during the digestive process.


Earth-worms are distributed throughout the world under the form of
a few genera, which externally are closely similar to one another.
The British species of Lumbricus have never been carefully
monographed; but we may judge of their probable number from those
inhabiting neighbouring countries. In Scandinavia there are eight
species, according to Eisen; {7} but two of these rarely burrow in
the ground, and one inhabits very wet places or even lives under
the water. We are here concerned only with the kinds which bring
up earth to the surface in the form of castings. Hoffmeister says
that the species in Germany are not well known, but gives the same
number as Eisen, together with some strongly marked varieties. {8}

Earth-worms abound in England in many different stations. Their