The gratifying news is not that Neil Simon has another hit with "Biloxi Blues." At this stage of his career, that is rather like announcing that Elizabeth Taylor has acquired another fiance'.

What is rewarding about the playwright's latest comedy, newly ensconced at the Neil Simon Theatre for what looms as a lucrative run, is that it prolongs and expands the qualities that made "Brighton Beach Memoirs" so endearing. It's as if Simon were no longer quite so hellbent on reasserting his reputation as the life of the theatrical party. The jokes and wisecracks that have always characterized -- indeed, cluttered -- his writing continue to work their way deeper into the fabric of his plays. Under the comic bark, there is a new warmth and a gentle truthfulness. Could the man be mellowing?

"Biloxi Blues" is the second play in Simon's projected autobiographical trilogy about coming of age in the 1930s and '40s. Like its predecessor, it stars Matthew Broderick, surely one of the most appealing actors of his generation, as Eugene Morris Jerome, the playwright's alter ego. If the timing holds, and the young actor matures at roughly the same pace it takes Simon to write further installments in his life history, there will be no reason to stop at three plays.

When last seen at the end of "Brighton Beach Memoirs," our hero had successfully navigated the shoals of an impoverished Jewish adolescence in Brooklyn, acquired a few rudimentary notions of sex, along with an eagerness to put them to use, and resolved to become a writer. Now the time is 1943, and he is on a train, heading south for boot camp with 12 pot roast sandwiches and a notebook in his duffel bag. To his earlier goals, he has added a third: "Not to get killed."

"Biloxi Blues" takes him through 10 weeks of basic training under a sadistic drill sergeant (Bill Sadler), who prides himself on "Old Army discipline" and has quixotic means of obtaining it. The material is certainly familiar enough: Eugene's five barracks mates are predictably odoriferous, stupid, bullying and horny. The mess hall food is unpalatable. The regulations are inane, and someone, although not necessarily the guilty party, has to pay for the slightest infraction. That usually means 100 push-ups or latrine duty. As a writer for the Phil Silvers/Sergeant Bilko TV series, Simon has mined this territory many times over.

And you can't say that "Biloxi Blues" breaks virgin territory when, on 48-hour leave, the recruits rush off to Gulfport, where their options are the USO dance, populated by young Catholic schoolgirls who might as well be shackled to nuns, or the town harlot, who peddles $5 bottles of perfume and black lace panties on the side.

Except that "Biloxi Blues" is an Army comedy with a difference -- a portrait of the artist as a young (service) man. It is Eugene's growth Simon is most interested in, his awakening to a world that doesn't adhere to the laws of logic or even fairness. Eugene will encounter anti-Semitism. He will suffer all the invasions of privacy that make Army life a dehumanizing, not to say embarrassing, obligation. One of his fellow recruits will be bounced out of the barracks and into the brig on charges of homosexuality.

By filtering such common experiences through the bright eyes and unfailingly quick mind of Eugene, however, Simon finds new life in the old fatigues. Eugene doubles as the play's narrator, as he did in "Brighton Beach," but he is no dispassionate observer. Like a puppy at the ocean's edge, he is eager to plunge into the waves; at the same time he keeps skittering back up on the sand. But he's keenly aware of the perpetual tug of war going on in his soul. Whether he's attempting to strike the properly worldly pose outside the prostitute's door or fishing for the one response that will soothe the drill sergeant's savage breast, he's forever juggling possibilities and weighing consequences.

Fate seems to have planted Eugene perpetually on the horns of a dilemma. Big or small, it elicits from him the same mixture of anxiety and exhilaration. Broderick orchestrates the two tones with instinctive brilliance. He can bring an audience into his complicity effortlessly, but never at the expense of the characters around him. He wants to stay neutral, "like Switzerland." But he's wonder-struck that some men sing popular ballads in their sleep, while others entertain round-the-clock erections, and he can't help sharing the revelations with us.

From one of his peers, a bespectacled Jewish intellectual who has chosen to buck authority every regimented step of the way, Eugene will even learn A Big Lesson: "Once you start compromising your thoughts, you're a candidate for mediocrity." Being everybody's pal may be less important than being your own man. Broderick tucks the advice away neatly, but the sudden reflectiveness in his eyes tells you it has registered. He's grown a peg.

World War II may have been the last war to inspire the kind of fraternal nostalgia that permeates "Biloxi Blues." The stage literature engendered by Vietnam -- a "Streamers," say, or a "Basic Training of Pavlo Hummel" -- depicts barracks life in far more irrational and violent terms. Military service, once thought to be a necessary passage to manhood, has come in more than a few quarters to be seen as a passport to madness. The bedrock decency of "Biloxi Blues" is bound to make the play look obsolete to some.

Memory, however, is clearly at work here. (Just look at the glowing antebellum plantation that set designer David Mitchell has provided as a backdrop for Eugene's first fleeting romance!) And memory should be granted its prerogatives. Whatever it was like at the time, Simon is looking back at this period of his life with affection and even tenderness.

The cast, under the direction of Gene Saks, responds with a freshness of energy and imagination that suggests no one ever faced a platter of chipped beef before or fell in love under paper streamers in a church basement. The dimwit, the lout and the waffler may be staples in every barracks, but Brian Tarantina, Matt Mulhern and Alan Ruck make the stereotypes ring true all over again. And Barry Miller strikes a note all his own as the intellectual shrimp who, armed only with Talmudic reasoning, takes on the Army itself.

One of the reasons they come so sharply into focus is that Sadler has given them a vivid martinet to rebel against. With a starched body that seems to have just come from the cleaners and a mind that functions not unlike Rasputin's, he represents all that is arbitrary and mindless about basic training. And yet under the steel plate in his skull, there is a kind of mad caring that his men will come to acknowledge.

Simon's comic universe is richer and more human for that. After all, his characters have long known how to get on one another's nerves. Now they're getting under one another's skin. They've always made us laugh. But with "Brighton Beach Memoirs" and "Biloxi Blues," they're starting to tug at our hearts. The famous mile-a-minute quips have taken on the glimmer of illumination. Where, one muses happily, will it end?

BILOXI BLUES. By Neil Simon. Directed by Gene Saks. Sets, David Mitchell; costumes, Ann Roth; lighting Tharon Musser. With Matthew Broderick, Bill Sadler, Barry Miller, Randall Edwards, Penelope Ann Miller, Matt Mulhern, Alan Ruck, Geoffrey Sharp, Brian Tarantina. At the Neil Simon Theatre.