The Metropolitan, In All Its Hilarity.

''Funny'' is a rare adjective for an exhibition at the Metropolitan Museum of Art. It just might apply, however, to ''Infinite Jest: Caricature and Satire From Leonardo to Levine,'' which opens there on Sept. 13. Constance McPhee, an associate curator in the Met's department of drawings and prints, said the idea for the show came to her about four years ago. ''I knew we had some Italian caricature drawings, and then we purchased one by Bernini,'' she recalled. [ABSTRACT FROM AUTHOR]