Each morning we look in the mirror. Perhaps we see a new line at the corner of one eye or an old line deepening at one corner of the mouth. If we do, we're entitled to wince a bit. In our country more than any other that I know of , we're locked into a culture which regards aging as almost indecent. Irving Wallace recognizes this, not only from observation as an author but from sad experience-he has just passed his 63rd birthday.

He's been writing, and getting paid for it, since his teens. During the past 20 years he has ranked as a prime practitioner in the underrated art of writing best sellers; he has become adept at entertaining millions. Of the novels before this one, "The Fan Club" is the most effective and sensational. In it he conjures up a hollywood sex star who's a cross between Marilyn Monroe and Joan Crawford and has her kidnaped by a gang of four men.

Unfortunately, "The Pigeon Project" is no "Fan Club," though the idea looks like a natural. An elderly Anglo-American gerontologist named Davis MacDonald has traveled to the part of our planet where the oldest people live. It's in the Soviet Union between the Black Sea and the Caucasus. There he's been doing research on longevity for the past six years. As the novel opens, he realizes that he's actually found a formula for doubling our span of life. It isn't a formula for a shallow but eternal youth nor for a lenghened life vitiated by constant aging; it's a formula which will prolong maturity.

Professor MacDonald wants to fly to Paris to proclaim his discovery at a world congress of gerontologists. However, a Russian spy in his household informs the KGB. Though the Soviets itch to save the formula for themselves, the professor manages to escape as far as Venice. By now you recognize the genre. It's the escape story, all ready for television or the movies. The main bad guys are the Russian pursuers; the main good guys are Americans, who do their best to save the professor.

The chief villain is Major Kedrov of the KGB. He has a brutally coarse nose and mouth, along with close-set eyes-and no reader of popular fiction expects anything good from anyone with close-set eyes. The hero is Tim Jordan, an American engineer and publicist who's gone a bit to seed during his last two years in Venice. Though his features remain attractively narrow and angular, his lean, athletic body has grown soft. The heroine is Alison Edwards, Ph.D. a colleague in gerontology of the professor's. She's the sort of Ph.D. you meet most in best sellers. Observe Wallace's description when Tim Jordan first sees her: "She was rather tall, maybe 5 feet 6, erect, poised, graceful, carrying a short beige jacket and wearing a blouse of some material which clung to her pointed, shimmying breasts." And she's in her mid-20s. Anyway, she quickly assures him that she has "a precise and logical mind."

Right after reaching the Venice airport, the professor is cought and imprisones in a monastery outside the city till he can be shipped back to the Soviet Union. Daily he feeds bread crumbs to the pigeons at the window of his cell. The third day he has an inspiration. You guessed it. He pens a call for help on a strip of paper, scoops up an unsuspecting pigeon, and ties the message to its leg. Tim Jordan, sipping tea in the Piazza San Marco, finds it. The paper directs the finder to phone Dr. Alison Edwards in Paris. Tim does so and the plot shifts inro gear.

The incidents leading to the climactic chase, by water of course, are interlarded with tourist-style descriptions of Venice. The characters who propel theplot include an Italian movie star compounded of Lollobrigida and Loren; a lovely, passionate Italian secretary; and a best-selling movelist, Cedric Foster. He's rather like Somerset Maugham. The way Wallace puts it, "he appeared virile and he wrote virile" but he was homosexual. When Foster accidentally learns of the formula he begs for a chance to use it. Age has gnawed away his creativity. The prose of old writers, he says in bitterness, is "eitless, childish, respected only because they've been around so long." Even worse, age has withered his physical appeal; has face and figure have grown flabby. What a marvel if the formula could make him young again even if he got to be 100! We can hear the resonance when Wallace writes about the aging Foster.

"The Pigeon Project" lacks the professional skill of "The Fan Club." The titles of the two novels illustrate the fact. The first has nothing to do with the idea of the book; the second is a suitably grim pun. It doesn't take a structuralist analyzing signs to show us that the term "pigeon project" is meaningless. Though the new novel will doubtless be a shiny commercial success, it will attract and hold far fewer readers than "The Fan Club." More than once the story becomes tedious, and as the late James M. Cain used to say, "You can't argue with boredom."

But what about an end to aging? It would be mean to give away the conclusion to the plot; but it's probably all right to hint to readers that aging, unfortunately, will still be with us.