Sorry I hurt you, old fellow," explained Dan, looking rather ashamed of himself.
"I understand.

The longing to pitch into somebody was so strong you couldn't resist.

You are a sort of Berserker, Dan, and something to tussle with is as necessary to you as music is to Nat," said Mr.Bhaer, who knew all about the conversation between the boy and Mrs.Jo.
"Can't help it.

So if you don't want to be pounded you'd better keep out of the way," answered Dan, with a warning look in his black eyes that made Jack sheer off in haste.
"If you want something to wrestle with, I will give you a tougher specimen than Jack," said Mr.Bhaer; and, leading the way to the wood-yard, he pointed out certain roots of trees that had been grubbed up in the spring, and had been lying there waiting to be split.
"There, when you feel inclined to maltreat the boys, just come and work off your energies here, and I'll thank you for it." "So I will;" and, seizing the axe that lay near Dan hauled out a tough root, and went at it so vigorously, that the chips flew far and wide, and Mr.Bhaer fled for his life.
To his great amusement, Dan took him at his word, and was often seen wrestling with the ungainly knots, hat and jacket off, red face, and wrathful eyes; for he got into royal rages over some of his adversaries, and swore at them under his breath till he had conquered them, when he exulted, and marched off to the shed with an armful of gnarled oak-wood in triumph.

He blistered his hands, tired his back, and dulled the axe, but it did him good, and he got more comfort out of the ugly roots than any one dreamed, for with each blow he worked off some of the pent-up power that would otherwise have been expended in some less harmless way.
"When this is gone I really don't know what I shall do," said Mrs.Jo to herself, for no inspiration came, and she was at the end of her resources.
But Dan found a new occupation for himself, and enjoyed it some time before any one discovered the cause of his contentment.