New York: Duell, Sloan & Pearce, (1950). 8vo. Black cloth, stamped in red. 634 p. 1st edition. Fine in fine d.w. 
Interesting collection of material, much of it from the left. Authors represented include Rosa Luxemburg, Karl Kautsky, Victor Chernov, Julius Martov, Bertrand Russell, Alexander Berkman, Emma Goldman, Victor Serge, Boris Souvarine, Max Eastman, Leon Trotsky, et al.