One of the lowest forms of tongues is that of the gasteropod. All snails and slugs are gasteropods. They have instead of a regular tongue a strip that is called a lingual ribbon, one end of which is free and the other fastened to the floor of the mouth. Across the ribbon from left to right run rows of hard projections almost like teeth. Whatever the mouth comes against is tested for food qualities by this rasping ribbon which files away at the substance and wears away not only what it works upon but the ribbon itself. This loss of tongue is no serious affair to the gasteropod, for he finds his tongue growing constantly like a finger-nail and he needs to work diligently at his trade or suffer from undue proportions of the unruly member. Snails in an aquarium gnaw the green slime from the sides of the vessel with their lingual ribbons, and the process may be seen to more or less advantage at times. Taste is not all confined to tongues. Some people have papillæ on the inside of the cheek. Medusae (Jelly Fish) have no tongues, but the qualities of the sea-water are noted by them. As soon as rain begins to fall into the sea they proceed directly towards the bottom, showing a decided aversion to having their water thinned in any way. Leeches show their powers of distinguishing tastes when they take in sweetened water quite freely, but suck at the skin of a sick man much less than at that of one in good health. Taste in insects has its probable seat in many instances in a pair of short horns or feelers back of the antennæ. These are constantly moving over the parts of that which the insect is feeding upon, and so apparently enjoyable is the motion of them that many scientists have concluded that these are the taste organs of the insects having them. At the same time it is quite probable that in all insects furnished with salivary glands, a proboscis, or a tongue, the power of taste is also or exclusively there. Fishes seem to do most of their tasting somewhere down in the stomach, for they pursue their prey voraciously and frequently swallow it whole. With their gristly gums, in many cases almost of the toughness of leather, there can be but little sensation of taste. Their equally hard tongues, many times fairly bristling with teeth constructed for capturing, but not for chewing, cannot possibly afford much of a taste of what is going down the throat with the rushing water passing through the open mouth and gills. Serpents which swallow their food alive can get but little taste of their victims as they pass over the tongue, although they are deliberate in the act and cover them with a profusion of saliva.