No second bidding was needed.  The door flew open with a bang; and the gravel of the play-ground, spurned right and left, dashed against the window panes as Martin flew across it.  The paling that fenced it off from the fields beyond was low, but too high for a jump.  Never a boy in all the school had crossed that paling at a spring, without laying his hands upon it; but Martin did.  We do not mean to say that he did anything superhuman; but he rushed at it like a charge of cavalry, sprang from the ground like a deer, kicked away the top bar, tumbled completely over, landed on his head, and rolled down the slope on the other side as fast as he could have run down,—­perhaps faster.

It would have required sharper eyes than yours or mine to have observed how Martin got on his legs again, but he did it in a twinkling, and was half across the field almost before you could wink, and panting on the heels of Bob Croaker.  Bob saw him coming and instantly started off at a hard run, followed by the whole school.  A few minutes brought them to the banks of the stream, where Bob Croaker halted, and, turning round, held the white kitten up by the nape of the neck.

“O spare it! spare it, Bob!—­don’t do it—­please don’t, don’t do it!” gasped Martin, as he strove in vain to run faster.

“There you go!” shouted Bob, with a coarse laugh, sending the kitten high into the air, whence it fell with a loud splash into the water.

It was a dreadful shock to feline nerves, no doubt, but that white kitten was no ordinary animal.  Its little heart beat bravely when it rose to the surface, and, before its young master came up, it had regained the bank.  But, alas! what a change!  It went into the stream a fat, round, comfortable ball of eider-down.  It came out—­a scraggy blotch of white paint, with its black eyes glaring like two great glass beads!  No sooner did it crawl out of the water than Bob Croaker seized it, and whirled it round his head, amid suppressed cries of “Shame!” intending to throw it in again; but at that instant Martin Rattler seized Bob by the collar of his coat with both hands, and, letting himself drop suddenly, dragged the cruel boy to the ground, while the kitten crept humbly away and hid itself in a thick tuft of grass.

A moment sufficed to enable Bob Croaker, who was nearly twice Martin’s weight, to free himself from the grasp of his panting antagonist, whom he threw on his back, and doubled his fist, intending to strike Martin on the face; but a general rush of the boys prevented this.

“Shame, shame, fair play!” cried several; “don’t hit him when he’s down!”

“Then let him rise up and come on!” cried Bob, fiercely, as he sprang up and released Martin.

“Ay, that’s fair.  Now then, Martin, remember the kitten!”

“Strike men of your own size!” cried several of the bigger boys, as they interposed to prevent Martin from rushing into the unequal contest.