20th-century art abstract (or non-representational) art. Cubism, generated by Picasso, Braque, Metzinger, Gleizes and others rejected the plastic norms of the Renaissance by introducing multiple perspectives into a two-dimensional image. Futurism incorporated the depiction of movement and machine age imagery. Dadaism, with its most notable exponents, Marcel Duchamp, who rejected conventional art styles altogether by exhibiting found objects, notably a urinal, and too Francis Picabia, with his "Portraits Mécaniques". Parallel movements in Russia were Suprematism, where Kasimir Malevich also created non-representational work, notably a black canvas. The Jack of Diamonds group with Mikhail Larionov was expressionist in nature. Dadaism preceded Surrealism, where
Crystal Cubism towards the end of 1916, with an art world still under the pressures of war, to show the parallels between the poetic theories of Guillaume Apollinaire of Max Jacob and himself in marking the burgeoning of a new era for poetry and artistic reflection. In "Nord-Sud" Reverdy, with the help of Dermée and Georges Braque, exposed his literary theories, and outlined a coherent theoretical stance on the latest developments in Cubism. His treatise "On Cubism", published in the first issue of "Nord-Sud", did so perhaps most influentially. With his characteristic preference for offense rather than defense, Reverdy launched an attack