German tax investigators have discovered a huge and previously unknown collection of art masterpieces, some of which was branded "degenerate" and seized by the Nazis. The 1,400 framed and unframed pieces include works by Pablo Picasso, Marc Chagall, Henri Matisse, and Pierre-Auguste Renoir. The hoard was reportedly found in the apartment of Cornelius Gurlitt, the son of a Nazi-era art dealer. Authorities are trying to determine which of the paintings, prints, and etchings may have been stolen by the Nazis and to whom they may rightfully belong.