Amongst the water weeds we shall probably find another small but striking creature, known as the sun animalcule, _Actinophrys Sol_. Why exactly it is called the sun animalcule we cannot say, probably it has earned its title from the fact that it resembles the conventional idea of the sun, with light rays radiating all round its circumference. The creature is whitish-grey in colour, spherical in shape and just visible to the naked eye. All over the surface of its body there are a number of apparently empty spaces, known as vacuoles--they probably account for its peculiar colour. Everywhere, it is studded with long, slender-pointed rod-like outgrowths. But rarely, the sun animalcule exhibits any movement and for long periods the only signs that it is living occur at feeding time. Its food consists of water animals and plants, of varying size. When a small animal comes into contact with one of the pointed rods, which radiate from the animalcule, it appears to be held there in some unaccountable manner and, after a pause, it begins a fateful journey by sliding down the rod to the spherical body of its captor. Then it is passed into one of the vacuoles and digestion very soon takes place. That it does not do so immediately is shown by the fact that the wheels of a wheel animalcule, which has been passed to the vacuole of our subject, continue their movements for a considerable period. When larger animal food is partaken of, a different method is pursued by the sun animalcule. A water-flea, for instance, coming into contact with one of the rods will struggle violently in its efforts to escape. Then the sun animalcule shows real signs of life, for some of the other rods bend over and hold the captive so that it, eventually, is passed to a vacuole. In our chapter on agriculture we mention a peculiar flat worm known as the liver fluke. This unpleasant creature has one or two relatives who make their home in ponds and, though they are not more beautiful than the liver fluke to look upon, they are quite harmless. One of these flat worms is about 3/4-inch long and not unlike an indian club in shape. It moves about, with some speed either by the aid of a sucker on its head or by a curious gliding movement. The other pond-frequenting flatworm is more like the liver fluke, its leaflike oval body, about 1/2-inch long, is pointed fore and aft. It is a common sight to see it gliding here and there in search of still smaller animals off which it may make a meal.