"Look, Señor Murillo, look!" exclaimed the youths, as they pointed to the easel of Mendez.

"Who has painted this—who has painted this head, gentlemen?" asked Murillo, eagerly. "Speak; tell me. He who has sketched this head will one day be the master of us all. Murillo wishes he had done it. What skill! Mendez, my dear pupil, was it you?"

"No, señor," replied Mendez, in a sorrowful tone.

"Was it you, then, Isturitz, or Ferdinand, or Carlos?"

But they all gave the same reply as Mendez.

"I think, sir," said Cordova, the youngest of the pupils, "that these strange pictures are very alarming. To tell the truth, such wonderful things have happened in your studio that one scarcely knows what to believe."

"What are they?" asked Murillo, still lost in admiration of the beautiful head by the unknown artist.

"According to your orders, señor," answered Ferdinand, "we never leave the studio without putting everything in order; but when we return in the morning, not only is everything in confusion, our brushes filled with paint, our palettes dirtied, but here and there are sketches, sometimes of the head of an angel, sometimes of a demon, then again a young girl, or the figure of an old man, but all admirable, as you have seen yourself, señor."

"This is certainly a curious affair, gentlemen," observed Murillo, "but we shall soon learn who is this nightly visitant. Sebastian," he continued, addressing a little mulatto boy about fourteen years old, who appeared at his call, "did I not desire you to sleep here every night?"

"Yes, master," said the boy, with timidity.