122 THE PRESERVATION OF MARINE ANIMALS
dies in the form of a shrunken, shapeless mass. Nevertheless, with
care and practice considerable success may be achieved.
One species of anemone, Anthea cereus, or Anemonia sulcata,
which is common enough on British coasts, is incapable of with-
drawing its tentacles and enclosing them within the contracted walls
of its body or "column." The difficulties involved in the preserva-
tion of most species are therefore absent in the case of this one.
When it is well expanded in a quantity of water just sufficient to
cover it, it is killed by the sudden addition of an equal quantity of a
mixture of chromic acid (1 per cent.) and picro-sulphuric1 acid in
equal parts. It is left thus for five or ten minutes, and then its base
is removed from its attachment and the specimen is suspended by
the margin of the base, tentacles downwards, in a 1/2 per cent.
solution of chromic acid; after half-an-hour in this it is transferred
to dilute alcohol, and subsequently to stronger alcohol.
Small anemones, such as Corynactis, and very small specimens of
larger species, may be killed with saturated solution of corrosive
sublimate poured over them in boiling condition.
The common red anemone, Actinia equina, or mesembryanthemum,
is to be killed with a boiling mixture of 100 parts saturated solution
of sublimate and 50 parts pure acetic acid, from which it is trans-
ferred after a second or two to chromic acid 1/2 per cent.
In the case of Heliactis bellis, Bunodes gallinaceus and B. rigidus,
when the specimen is fully expanded, the sea water is siphoned off
from the vessel containing it until only enough is left to cover the
specimen, and then a volume of chloral hydrate solution, 2 per 1,000,
twice as large as that of the water left is added. This anaesthetizes
the animal, and after a couple of minutes it is removed in the same
manner, and cold concentrated solution of corrosive sublimate is
poured in in considerable quantity.
To anaesthetize Adamsia rondeletii (the anemone which grows
always on whelk shells inhabited by the large hermit-crab, Eupagurus
bernhardus), tobacco smoke is employed. The specimen in a beaker
with sea water is placed in a shallow dish containing a little water,
and covered with a bell-jar. A metallic pipe filled with strong
tobacco is fitted to a small pair of bellows and the tube introduced
beneath the edge of the bell-jar; a small bent glass tube is also fitted
beneath the edge of the jar to allow air to escape. By working the
1 Picro-sulphuric acid is made by adding two parts of sulphuric acid per cent. to a saturated
solution of picric acid in water, then filtering and diluting the mixture with three times its
volume of water.