Bart is a man.  He had the face and form of a man, but his instincts were as old as the ages.  The animal world obeys him.  Satan neighs in answer to his whistle.  The wolf-dog licks his hand at the point of death.  There is the profound difference, always.  You try to reconcile him with other men; you give him the attributes of other men.  Open your eyes; see the truth:  that he is no more akin to man than Black Bart is like a man.  And when you give him your affection, Miss Cumberland, you are giving your affection to a wild wolf! Do you believe me?”

He knew that she was shaken.  He could feel it, even without the testimony of his eyes to witness.  He went on, speaking with great rapidity, lest she should escape from the influence which he had already gained over her.

“I felt it when I first saw him—­a certain nameless kinship with elemental forces.  The wind blew through the open door—­it was Dan Barry.  The wild geese called from the open sky—­for Dan Barry.  These are the things which lead him.  These the forces which direct him.  You have loved him; but is love merely a giving?  No, you have seen in him a man, but I see in him merely the animal force.”

She said after a moment:  “Do you hate him—­you plead against him so passionately?”

He answered:  “Can you hate a thing which is not human?  No, but you can dread it.  It escapes from the laws which bind you and which bind me.  What standards govern it?  How can you hope to win it?  Love?  What beauty is there in the world to appeal to such a creature except the beauty of the marrow-bone which his teeth have the strength to snap?”

“Ah, listen!” murmured the girl.  “Here is your answer!”

And Doctor Randall Byrne heard a sound like the muted music of the violin, thin and small and wonderfully penetrating.  He could not tell, at first, what it might be.  For it was as unlike the violin as it was like the bow and the rosined strings.  Then he made out, surely, that it was the whistling of a human being.

It followed no tune, no reasoned theme.  The music was beautiful in its own self.  It rose straight up like the sky-lark from the ground, sheer up against the white light of the sky, and there it sang against heaven’s gate.  He had never heard harmony like it.  He would never again hear such music, so thin and yet so full that it went through and through him, until he felt the strains take a new, imitative life within him.  He would have whistled the strains himself, but he could not follow them.  They escaped him, they soared above him.  They followed no law or rhythm.  They flew on wings and left him far below.  The girl moved away from him as if led by an invisible hand, and now she stood at the extremity of the porch.  He followed her.

“Do you hear?” she cried, turning to him.

“What is it?” asked the doctor.

“It is he!  Don’t you understand?”

“Barry?  Yes!  But what does the whistling mean; is it for his wolf-dog?”