"Sigmar Polke is a pretty nutty guy," a friend of his told me at the press preview for the show of Polke's early drawings at the Museum of Modern Art. "When he draws he really is like a child. He bends close to the paper, shutting out everything else except what he's working on. And he laughs to himself. You may not think his drawings are funny, but he does."

It's true, some of the 160 works (and 20 notebooks) on view at MoMA are funny. Of course they are. We're talking about a guy named Polke who adopted polka-dots as a personal motif as soon as he could draw a little circle.

His ballpoint pen drawings of women's faces, done in 1963 when the artist was 22, are just plain goofy. His 1966 drawing of a man whose erect necktie points skyward would interest Freud as well as the editors of "Sex to Sexty." And his 1968 watercolor of an "L" shape on graph paper, captioned "Higher Beings Command: Paint an Angle!" is just -- well, if you don't get it by now, as Mr. Natural said, don't mess with it.

Born in 1941, Polke was brought up in Düsseldorf and became a star pupil of Joseph Beuys at the Staatliche Kunstakademie. In 1967, along with Gerhard Richter and the late art dealer Konrad Fischer, Polke opened a storefront gallery and launched Germany's answer to Pop Art, which they called Capitalist Realism. Polke specialized in slight and awkward cartoons that parodied modern art and pop culture, all doodled with felt-tip pen and spray paint on crappy paper or patterned fabric.

Polke was (and apparently still is) a freewheeling, nihilistic Dionysius to Richter's (and Warhol's and even Rauschenberg's) classicizing Apollo. Then again, maybe he's the class dunce, as suggested by a 1963 drawing, A-Man, that MoMA drawings curator Margit Rowell says may be a self-portrait.

Rowell confessed that after a detailed survey of all of Polke's works on paper she ended up spurning his more finished Pop efforts in favor of a selection of early drawings that are "primitive, scrubby and childish." The idea is that Polke's work provides a look into the depths of a child's psyche, where can be discovered an innocent and pure expression.

Lots of the drawings have a political edge, and can be read as light-hearted critiques of German life. The 1964 cartoon showing a flute of champagne surrounded by confetti and three drunken celebrants is titled "Champagne for All", a sentiment that is "typically German," according to critic (and German native) Klaus Ottmann. "And it's not even real champagne, since it's not French!"

Another drawing portrays Khruschev and Nixon as "potato heads," one of a series of works using the reference. "Some people eat magic mushrooms to expand their awareness," Rowell said Polke told her. "What can you expect from people who eat potatoes?"

Other works are parodies of modernist abstraction, a theme that seems tired today but was probably fresher back in the '60s. The drawing Shirts in All Colors (1963) links utopian color abstraction to the world of contemporary commodities. A series of works from 1966, called Baroque Group, almost seems honest in its attempt to create "lovely" post-Kandinsky abstractions. Somehow they aren't convincing.

The exhibition's tour de force is a gallery containing four large trippy works referring to infinity and modern physics and dated 1969-71. They're sloppy doodles on a huge scale, stained and splattered and scrawled upon. More than anything else these works resemble a drug-induced attempt to do a summing up, a kind of latter-day Large Glass.

Polke began as the maker of trashy jokes, an anti-art that mocked the academy, the museum and the art market. Today his major paintings -- which in fact are not so different from the works shown here, though they are far more interesting visually -- are considered beautiful and sell for upwards of $500,000 at auction. What can explain this contradiction?

By the way, it seems to be parody season at MoMA. The museum's current surveys of British Pop prints and comic drawings are full of jokers. The same could be said of the just-closed exhibition of samplers by Elaine Reichek (quite accomplished technically and very inventive) in the Projects Room. But the greatest offender is "The Museum as Muse: Artists Reflect," Mar. 14-June 1, 1999, an exhaustive survey of the century-long effort to convert culture to kitsch.

I've got to say, that after all this I was more than ready for the 1951 Ellsworth Kelly color abstraction on view up in the galleries on the second floor.