182
THE ESSEX NATURALIST.
importance, yet they are very abundant and widespread : their
dispersal is probably much helped by the unconscious agency of
men and animals, including birds, and by general traffic; such
also is the way in which the seeds of Grasses, Goosefoot, Trefoil,
Plantain, etc., may be distributed. How such comparatively
rare casuals as Galinsoga or the True Wormwood arrived, we
can only guess. In conclusion I should like to thank Miss E. A.
Greaves for her unfailing help with maps and herbarium material.
THE MOULTING OF A BIRD-EATING SPIDER.
By WILLIAM HEELEY, B.Sc.
[Read 31st October, 1936.]
(With 1 Plate.)
FOR some time past we have had on exhibition in the Stratford
Museum a large poisonous bird-eating spider—a member
of the family Aviculariidae. It was found, alive, in a crate of
bananas in Stratford Market, and had evidently been accidentally
brought over with them from the West Indies.
We have succeeded in keeping it alive by feeding it on
cockroaches chiefly, and about three weeks ago I had the
interesting experience of watching the creature cast its skin.
The process took about five hours, and after the moult was
completed I managed to get the cast skin away, and found that
it was perfectly whole, and a really beautiful specimen of a
moult. The spider itself has survived the moult without the
loss of any limbs, and is still very much alive, in its beautiful
new coat.
I had noticed for some time before the moult occurred
that the spider seemed listless and refused to eat, lying huddled
up in a corner with its legs tucked tightly beneath it, and I
was afraid it was dying. I observed nothing further until
the actual day when the moult occurred. Then I noticed that
the carapace was splitting along each side and along the front,
the splitting spreading as the spider alternately contracted
itself and then expanded again, until the carapace was loose
all round except for the narrow portion connecting the thorax
and abdomen. This part formed a sort of hinge, on which the