Digestion in Roman snails does not happen like it does in humans: The stomach,
for example only is a blind sack, where food is dammed up to be better digested.
The main digestive gland is often called the snail's liver, but serves
considerably more purposes than simply producing digestive fluids, it also
digests food and stores nutrients, it even retrieves calcium carbonate from a
snail's food.
A snail's excretion happens it its kidney. Here waste matter mainly made from
nitrogen compounds is filtered from the blood, but at the same time water is
retained, so the Roman snail finally excretes a viscous paste of ureic acid.
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