There was a king in Erin long ago who had thirteen sons, and as they grew up he taught them good learning and every exercise and art befitting their rank.
One day the king went hunting, and saw a swan swimming in a lake with thirteen little ones. She kept driving away the thirteenth, and would not let it come near the others.
The king wondered greatly at this, and when he came home he summoned his Sean dall Glic (old blind sage), and said: "I saw a great wonder to-day while out hunting,—a swan with thirteen cygnets, and she driving away the thirteenth continually, and keeping the twelve with her. Tell me the cause and reason of this. Why should a mother hate her thirteenth little one, and guard the other twelve?"
"I will tell you," said the old blind sage: "all creatures on earth, whether beast or human, which have thirteen young, should put the thirteenth away, and let it wander for itself through the
