Yooks and Zooks! Dr. Seuss (properly pronounced, it rhymes with Royce) has entered the atomic age. His latest work, ''The Butter Battle Book,'' to be published today to mark his 80th birthday, is an arms race allegory that welcomes two new creatures to the Seuss menagerie - the Yooks and the Zooks.
They look the same. But their clothing is different, and, most important, they butter their bread on opposite sides (hence the title). Says a sign on the wall that separates the groups, ''Yooks are not Zooks. Keep your butter side up!''
The trouble begins when a Zook slings a shot at a Yook. The chief Yookeroo tells the hurt Yook: We'll dress you right up in a fancier suit! We'll give you a fancier slingshot to shoot! And he ordered the Boys in the Back Room to figger how to build me some sort of a triple-sling jigger.m
And the arms race was on.
All the weapons the Yooks invent the Zooks match. At the end of the book, the Yook Boys in the Back invent the Big Boy Boomeroo . . . and the Zooks do too. On the last page, a Yook and a Zook are poised on the wall, each holding his Big Boy Boomeroo. Who will drop his first?
''We'll see. We will see. . . .'' And thus the book ends.
The book has the familiar Seuss bounce and charming illustrations. And the pace is so quick the pages turn themselves. But loyal readers might ask, ''What happened to the Cat in the Hat? Or the messy house that gets picked up in a minute flat?''
Theodor Seuss Geisel, the author's real name, has said that 1984 is a different time from 1953. And children know so much more about the world. If they know anything at all about the world, they know about the arms race.
Besides, this isn't the first time politics has found its way into a Seuss book. ''Yertle the Turtle'' was based on Hitler; ''Sneetches'' deals with racism; ''How the Grinch Stole Christmas'' strikes out against the commercialization of that holiday; and ''The Lorax'' comes down on pollution.
Geisel (who was unavailable for interview) hadn't set out to write ''message books.'' He has said that his outlook is firmly based in reality, and calls his books satire and not whimsy.
Whimsy is based on nothing, and his books, Geisel says, are based on the world.
''The Butter Battle Book'' is probably the most thinly veiled allegory Geisel has written. It's not a funny book. Clearly, he feels seriously about the arms race.
The book ends on a questioning note - will mankind blow itself up? Geisel was tempted to give it a happy ending, but, as he told one reviewer, ''I would have gotten into dishonesty. That's the situation as it is.''
Geisel has had this kind of clear-eyed realism throughout his career. Claiming not to write for children, he has always said he doesn't know if his books are children's books for adults or adults' books for children. He writes for himself, and that way the books come out somewhere between the two.
To some parents ''The Butter Battle Book'' may not seem like ideal children's fare. The book depends heavily on the implicit urgency of the arms control issue. We all know it is important (so the argument goes) and therefore our children should know about it. But should they?
What Geisel rather disparagingly calls ''a happy ending'' may in fact be the ray of hope that children need when learning about adult troubles.
It is not fashionable to be optimistic about the nuclear arms race. But, if the future of the world rests with children, shouldn't they learn that, in addition to seeing evil, mankind is capable of averting it as well?