Context: The river Chobe, discovered by the author, flows in South Africa and is a natural habitat of dangerous creatures like hippos and crocodiles. Except some ill natured ones, the hippos are less furious than crocodiles until they are disturbed. Crocodiles of the river are so much daring that they carry off calves and seize even Cows.
Explanation : In these lines the writer tells us about the food of crocodiles and how they attack a man. The chief food of crocodile is fish-either large or small. The crocodiles have broad scaly tails and with the help of their tails they catch fish. When a crocodile sees a man on the other bank of the river, he runs atonce at a very high speed at the bottom of the river. So his body is not seen on the surface of water. But his speedy motion inside the water makes small waves on the surface and this is the indication that a crocodile is coming at a high speed inside the water.
