Guillaume Corneille Nu Vert Et L'Oiseau.. Corneille, stage name of Cornelis van Beverloo. He studied in Amsterdam, though in reality, he was considered self-taught. In 1948 he joined the group Cobra. In 1950 he traveled to Paris where he became friends with Karel Appel. He developed a style of expressive abstraction. His work shows the influence of Picasso and Miró.