The Janus Film Festival continues its week-long engagement at the Harvard Sq. Theater. The festival features two classic new wave films per day, and if there is any problem with the movies it's that they are all too good to be taken in such short order. You get a good does of great Bergman this weekend, with The Seventh Seal tonight and Wild Strawberries on Sunday. Renoir's The Rules of the Game, one of the best social-political movies ever made, is showing tonight, followed on Saturday by The Grand Illusion, Renoir's anti-war film about the 1914 world conflict. Welles's adaptation of Booth Tarkington's The Magnificient Ambersons is okay, but doesn't really belong with these classics. Monday night's Marx Brothers comedy, Room Service, is hardly one of their funniest and you should probably see Annimal Crackers in Boston instead. The 39 Steps, also playing Monday, is one of the best mysteries that Hitchcock (or anyone) ever made.

The Organizer, a relatively obscure but reportedly excellent film about the politics of the Italian Left at the end of the 19th century, is showing at the Science Center tonight and tomorrow at 7 and 9:30. Marcello Mastroianni stars in this film made in 1963 by director Monicelli. Tickets are $1.50.

Julius Caesar is the first Shakespeare play that they make you read in high school, but that's not necessarily a reason to dislike it. There are some reasons for disliking the movie version that's coming to the Welles on Sunday. Marlon Brando, who stars as Et Tu Brute, just don't make a good Roman no way. The rest of the cast is starchy and lifeless, wringing the play dry of all its verve. The Welles Shakespeare co-feature, A Midsummer Night's Dream, is really enjoyable.