suspicious minds wrote:


"bigboard" wrote in message

While they don't strictly speaking have gizzards, they do need some sort
of
gritty substance to help break up the food they ingest. I use calcified
seaweed.

Read this then

"In most of the species, the oesophagus is enlarged into a crop in front
of the gizzard. This latter organ is lined with a smooth thick chitinous
membrane, and is surrounded by weak longitudinal, but powerful transverse
muscles. Perrier saw these muscles in energetic action; and, as he
remarks, the trituration of the food must be chiefly effected by this
organ, for worms possess no jaws or teeth of any kind. Grains of sand and
small stones, from the 1/20 to a little more than the 1/10 inch in
diameter, may generally be found in their gizzards and intestines. As it
is certain that worms swallow many little stones, independently of those
swallowed while excavating their burrows, it is probable that they serve,
like mill-stones, to triturate their food. The gizzard opens into the
intestine, which runs in a straight course to the vent at the posterior
end of the body."

THE FORMATION OF VEGETABLE MOULD
THROUGH THE ACTION OF WORMS
WITH OBSERVATIONS ON THEIR HABITS.
by Charles Darwin


[FIRST EDITION, October 10th, 1881.]

CHAPTER I--HABITS OF WORMS.
http://www.webmesh.co.uk/darwinworms1.htm



I hadn't realised the organs were called gizzards. Still, my point about
their digestion still stands.

--
A free society is one where it is safe to be unpopular.
-- Adlai Stevenson