There is a “worm snail” that builds great limestone causeways and bridges. This is the shelled sea-snail of the Mediterranean—Termetus (wormlike). When the creature is young its shell is a regular spiral which the owner, free to move about, carries on its back and into which it can retreat when alarmed. As the snail ages the shell becomes twisted and contorted, like a tube, and is attached to an offshore rock. The animal crawls inside and soon dies. There are inestimably great numbers of these gastropods. They fix their shell tombs close together. These coil around each other to form solid masses of rock. Quatrefages, describes them in these words: “In Sicily where calcarous rocks projected into the sea I found they were surrounded by a kind of causeway which, without varying much in width, yet followed all the sinuosities of the shore almost exactly on a level with the surface of the water, filling up narrow chasms in some places and forming solid archways in others. Thus it afforded a smooth and easy path to one who did not object to having his legs washed by the waves. One might suppose the white and compact cement had been consolidated by man.” The love life of some snails is confusing to Freudians. Each animal is provided with a quiver full of arrows, located in the right side of the neck. These darts can be discharged with considerable force. They are straight or curved shafts of carbonate of lime which taper to exceedingly fine points. During the breeding season the little mollusks meet in pairs. A couple will station themselves about an inch apart and start shooting at each other. Several darts are exchanged and each finds its mark. After this love duel the two embrace and, since each is both male and female, both lay eggs. The darts presumably were first developed as defense weapons and, outmoded for service of Mars millions of generations ago, now have been turned to the service of Eros. Showers of snails have been reported intermittently. One of the most notable took place back in 1892 at the German town of Padeborn. Late in August a great yellow cloud was seen over the town. In a few minutes it burst into a torrential rain. Afterwards the pavements were covered with water snails, all with shells broken after their long fall from the sky. Some snails can bore holes in solid rock. One, found chiefly on the French channel coast near Boulogne, has bored holes six inches deep and an inch in diameter with a cup-shaped cavity at the bottom. The cavity is used for the animal’s hibernation. A few snails are natural barometers. They reputedly are extremely sensitive to changes in humidity. One, generally grey, turns yellow just before a rain and blue afterwards.