“Dad didn’t like the idea.  He was afraid of what Dan might become.  And he was right.  One day, in a saloon that used to stand on that hill over there, Dan had a fight—­his first fight—­with a man who had struck him across the mouth for no good reason.  That man was Jim Silent.  Of course you’ve heard of him?”

“Never.”

“He was a famous long-rider—­an outlaw with a very black record.  At the end of that fight he struck Dan down with a chair and escaped.  I went down to Dan when I heard of the fight—­Black, Bart led me down, to be exact—­but Dan would not come back to the house, and he’d have no more to do with anyone until he had found Jim Silent.  I can’t tell you everything that happened.  Finally he caught Jim Silent and killed him—­with his bare hands.  Buck Daniels saw it.  Then Dan came back to us, but on the first night he began to grow restless.  It was last Fall—­the wild geese were flying south—­and while they were honking in the sky Dan got up, said good-bye, and left us.  We have never seen him again until to-night.  All we knew was that he had ridden south—­after the wild geese.”

A long silence fell between them, for the doctor was thinking hard.

“And when he came back,” he said, “Barry did not know you?  I mean you were nothing to him?”

“You were there,” said the girl, faintly.

“It is perfectly clear,” said Byrne.  “If it were a little more commonplace it might be puzzling, but being so extraordinary it clears itself up.  Did you really expect the dog, the wolf-dog, Black Bart, to remember you?”

“I may have expected it.”

“But you were not surprised, of course!”

“Naturally not.”

“Yet you see that Dan Barry—­Whistling Dan, you call him—­was closer to Black Bart than he was to you?”

“Why should I see that?”

“You watched him a moment ago when he was leaning over the dog.”

He watched her draw her dressing gown closer about her, as though the cold bit more keenly then.

She said simply:  “Yes, I saw.”

“Don’t you see that he is simply more in tune with the animal world?  And it’s really no more reasonable to expect Black Bart to remember you than it is to expect Dan Barry to remember you?  It’s quite plain.  When you go back to the beginning man was simply an animal, without the higher senses, as we call them.  He was simply a brute, living in trees or in caves.  Afterwards he grew into the thing we all know.  But why not imagine a throw-back into the earlier instincts?  Why not imagine the creature devoid of the impulses of mind, the thing which we call man, and see the splendid animal?  You saw in Dan Barry simply a biological sport—­the freak—­the thing which retraces the biological progress and comes close to the primitive.  But of course you could not realise this.  He seemed a man, and you accepted him as a man.  In reality he was no more a man than Black