“Frank is right,” said Uncle George, laughing. “This is not the common field daisy. It is the _ox-eye_ daisy. You might bring me a common daisy, Frank. I am sure there are many growing near. Ah, here is one at our feet! Now let us hold them side by side. “You can see that they are unlike one another in many ways. The _ox-eye_ daisy has much larger leaves and flowers. It bears its leaves and flowers on tall, strong stalks. The leaves of the common daisy lie almost flat on the ground, and there is only one little flower-head on each stalk. When we get home we shall look at them both more closely.” “Oh, look at those big yellow daisies growing among the corn,” said Dolly. “And I see some blue flowers near them,” said Tom. “The yellow flower is the _moon-daisy_. It is also called the _corn-marigold_. It is a great deal like the two daisies we have just been talking about. The other is the blue _cornflower_. It belongs to the same great family as the daisies. Frank will go and fetch us some.” Frank gathered a bunch of both flowers. He was just reaching over for some large red poppies when he saw a pair of small black cunning eyes peering at him. Then a brown creature ran past him and went out of sight among the long grass at the edge of the field. “A rat! a rat! Uncle George!” he shouted. “Yes, it is a rat, I saw it,” said his uncle. “But what is he doing out in the fields?” said Frank. “I always thought that rats lived in houses.” “The brown rat lives where he can,” said Uncle George. “Very likely this one has come from the farm. Farm-yard rats often come out and live among the long grass and reeds in summer-time. When the cold weather comes, and the crops are gathered, they go back to the stables and barns. There they rob the farmer. They are very cunning creatures. They steal eggs, milk, grain, and even kill and carry away young chickens. The rat lives by thieving. That is why he is killed whenever he shows his face. “Rats are sometimes useful, though. They swarm in ship docks and places where stuff is left about. They eat up what would rot and poison the air. They thus help to keep down disease. “Now, boys, before we go home I am going to show you something. I found it the other day when taking a walk.” Uncle George led the children to the end of the field, and pointed to a strange object among the corn. It was a nest of some sort. It was made of dried grass, and hung from five or six wheat stalks. It was round like a cricket-ball, and just about as big. “It is the nest of the harvest-mouse,” said Uncle George in a low voice. “Keep still, and perhaps we shall see Mistress Mousie.” The children waited a long time looking at the curious little object. At last a tiny brown creature ran up one of the wheat stalks and went into the nest. It seemed to go right through the wall of its little house. There was no hole to be seen where it went in. Then Uncle George clapped his hands. At once two wee brown mice came out.