What material is a snail's silvery trail?

This topic is not for the squeamish ones. There are many people who look down their noses at the humble snail and many others who turn up their noses at the thought of all slippery and slimy creatures. This is too bad because more information about the snail's silvery trail may help us finally to master the sniffly cold. The snail is classified as a gastropod because his one and only foot is a pliabla, leathery muscle on the underside of his stomach. The term “Gastropod" is coined from two older words meaning stomach and foot. It travels naturally at a snail's pace, by mak¬ing wavy motions along his muscular foot. But the ground and the grasses are too rough for the sturdy foot to slide smoothly along. To overcome this handicap, the snail sec¬retes a slimy mucus substance as he goes. The foot slides smoothly along on top of it, leaving a silvery trail of used mucus behind him. Mucus substances are very common throughout the animal world, more so than most people think. Certain fish ...  more