“The sooner you begin the better,” said Mrs. Polly; “and come back and report to me when you are through.”

The sparrow flew off and lighted on the ground under the nest. A flower-bed stood there, and he made a careful examination. Not a leaf was out of place that he could see, and not a plant disturbed in any way.

Then he pushed the branches carefully aside and examined the ground.

“Aha!” said the sparrow, with a satisfied little nod; “I begin to smell a mice. Somebody’s been here, that’s certain; but whether these tracks were made by a bird or a chicken or—” and he brought his bright little eyes nearer the ground. Yes, he was pretty sure now. The soft earth was marked by the traces of little feet, but so close together that he couldn’t make out the exact form; but just beyond were several larger ones, and he thought he knew to whose feet they belonged. “I guess I know whose foot that shoe will fit,” he said to himself.

Next he looked up towards the nest. A nasturtium vine was trained against the pillar, and pieces of twine formed a trellis for it to cling to. The sparrow ran his eye carefully over it. “I thought so,” he said to himself; “’twas he.”

The delicate leaves of the plant were broken in several places, and hanging to the stem; and in one place the stem itself was torn away from the twine as if too heavy a strain had been brought to bear on it.

The sparrow had seen enough to satisfy himself, and flew back to Mrs. Polly.

“Well?” she asked inquiringly.

“Well,” answered the sparrow, “I guess I’ve as good as caught the fellow.”

“Tell me what you found, and I’ll draw my own conclusions,” said Mrs. Polly, putting her head on one side with the knowing expression she always assumed when listening to a story.