Gene Davis has a two-part mind. To understand his art you have to read between the stripes.

His stripes have made him famous. Since the '50s he skillfully has deployed them in hundreds, perhaps thousands, of elegant, melodious, admired color paintings. But that elegance never has kept Davis from the goofy. His strictness does not mean that he hates the free. Davis plays in prison. His loyalty to format never has been total.

Behind those colored bars lives another sort of painter, one who loves the sexy, the whimsical, the new. That less-well-known Gene Davis, a sort of a subversive, flirts with fads and fashions, scribbles with abandon, and time and time again pokes fun at his twin. The two of them, together, have made the big new paintings now on exhibition at Middendorf/Lane Downtown, 404 7th St. NW.

These pictures are at once imposing and preposterous. The biggest and the littlest (some are small as calling cards, some are nearly nine feet tall) repeat--instead of colored stripes--hairless, open-mouthed, black silhouetted heads.

Now, what is one to make of that half-cartoony image? Is it a self-portrait (Davis, too, is wholly bald), or a wowed acknowledgment of the "new figuration" (also called "Bad Painting") that is now so much in vogue. Perhaps it is intended to make one think of Henry, that little, also hairless hero of the comics. Davis, one remembers, once reported for the Washington Daily News, and as long ago as 1958 put Snoopy in his art. He likes to play, wildly, with scale. His smallest "Micro-paintings" of 1968 were no bigger than postage stamps; his "Franklin's Footpath" (1972) was 414-feet long. He also enjoys clues. In 1971, he produced a drawing which he accurately titled "The Artist's Fingerprints Except for One Which Belongs to Someone Else." That painted head belongs to Davis in more ways than one. While its strict reiterations summon up his stripes, its you've-got-to-be-kidding look calls to mind, on purpose, the half-dumb, half-smart spirit of his other works of art.

Davis once upon a time was an abstract expressionist painter. He in a sense remains one. In his drawings and small paintings--and behind the broken orders of his most austere stripe paintings--one detects his trust in the active, unplanned, nearly automatic gesture. Two other sorts of paintings, both of them spontaneous, but in different ways, are included in this show.

His "Symbol Paintings" here are structured by ruled lines that run from left to right, like those one might find on a musician's score. Scattered on those staffs like so many notes are all sorts of little symbols--$'s and %'s and *'s, swastikas and question marks, spade's, club's, diamond's and heart's. Davis, in these airy works, suggests the musicality, the sense of beat and interval that so often has determined the colors of his stripes.

The 68 small pictures hanging in the back room have folk art's naive boldness. Only in the freshness of their wonderfully tuned colors does one see a sign of the better-known Gene Davis, the wealthy and renowned Washington Color Painter. The stripes within them wobble, their fields of color drip. Their oddly touching images--blocky trucks, combs, squiggling snakes, tennis rackets, dumbbells--look as if they might have been painted by a child.

That is no condemnation. At the core of his accomplishment there throbs a sort of innocence, an endless curiosity, a bright delight in new-found toys, an insistence upon play. Davis, although 62, is a kind of child still.

Well-known he may be. But his art, in all its oddness, verve and fearless foolishness, is not yet known well. The tiny and the huge, the serious and the frivolous, the gracious and the gross still war in his paintings. There has long been in his spirit a cleavage, a division, that the present exhibition does much to resolve. It will remain on view through March.