These fins all help to make the fish the splendid swimmers that they are, and are large and strong, or small and weak, according to which part of the water the fish inhabits. If he prefers the surface of the ocean, or a large body of water, his fins must be large enough, and strong enough to battle against fierce waves, and strong tides, while the fish who lives far below where the water is more calm finds his weaker fins ample for his needs. The long, oval body which most fishes possess is another great help in gliding rapidly through the water. Like others of his kind Sammy had a very strong spine in which was an air-bladder. By pressing the air out of this he could swim easily at a great depth, and by inflating it to let the air in, like a balloon, he could rise and swim along the surface. Sammy's eyes were large and round, and he could see splendidly, especially when the water was clear. His hearing, as well as his sense of smell was also good, and he breathed through the gills on each side of his throat. When taken out of the water the fish really dies of suffocation, for the water that enters its throat and flows out through the gills is the air that keeps it alive. Sammy's maiden aunt, an old fish who lived in the same stream with him, used to tell strange tales of fish that can live several days out of water by reason of the different formation of their gills. One of these is a tropical fish called the Anabas. It has very strong Pectoral fins which it uses like feet when on land, and it will even climb trees to catch the insects which it eats. Another fish of this sort is the Frog-Fish, a hideous creature which is caught near Asia. It can crawl about a room, if shut up in one, and looks exactly like an ugly frog. But the most wonderful of all is a South American fish called the Hassar. It usually lives in pools of water inland, and if the pool where it is happens to dry up, it will travel a whole night over land in search of a new home. It is an experienced traveler, and is said to supply itself with water for its journey. If the Hassar finds all the pools and streams dried up, it will bury itself in the sand, and fall into a kind of stupor until the rainy season comes around and brings it back to life. "Aunt Sheen," so called from the beauty of her skin, used to tell Sammy another story about this famous fish. It seems that the Hassar builds a nest just like a bird, only hers is under water along the reeds and rushes of some shore. The nest is made of vegetable fibres, and is shaped like a hollow ball, flat at the top. From a hole in this ball the mother can pass in and out, and she watches over her nest with the most tender care, until the young ones leave it. Fishermen catch the Hassar by holding a basket in front of the nest and beating it with sticks. When the poor mother comes out to defend her family, she falls into the basket and is captured.