Uccello was a most laborious student of animal life and so absorbed in the mysteries of perspective that he preferred them to bed; but he does not seem to have been able to unite them.

He was a perpetual butt of Donatello.

It is told of him that having a commission to paint a fresco for the Mercato Vecchio he kept the progress of the work a secret and allowed no one to see it.

At last, when it was finished, he drew aside the sheet for Donatello, who was buying fruit, to admire.

"Ah, Paolo," said the sculptor reproachfully, "now that you ought to be covering it up, you uncover it." There remain a superb nude study of Venus by Lorenzo di Credi, No.