With this entry, “Endpapers” ends. It may...

With this entry, “Endpapers” ends. It may return some day, but the date is not now to be named. I have enjoyed writing it for these first six months of my tenure as book editor, but I conclude, a little reluctantly, that the interests of The Book Review will be better served if I spend more time choosing books for other writers and less time writing about them myself. I might add, lest there be any whisper of censorship, that I take this decision unprompted.

How are books chosen for review? No question to a book editor is more predictable, and none is more in order. The selection process is a kind of panel discussion inside a single mind. I take the occasion of this last column to illustrate it both because the question is so frequent and because the time I will now not spend on “Endpapers” will be spent thus.

Last June Knopf published a book by Albert Rosenfeld entitled “Prolongevity II.” The “II” of the title is an unusually clear indication that this is a second, revised edition. One count, then, against a fresh review: Second editions are rarely all that different from first editions.

The subject of both editions of “Prolongevity,” however, is aging: what science knows about its causes and what medicine is beginning to do about its ravages. A coined word, the title elides prolonging and longevity. Now, this is a field in which advances are rapid, and the first edition of Rosenfeld’s book appeared fully 10 years ago. After the lapse of 10 years, even a straight reprint may on occasion be reviewed as if it were a new book. So, the “II” need not count against “Prolongevity II.” But how important is its topic?

In any brief period, certain topics force themselves on our attention. Even mediocre books on these topics win review attention if they arrive early, and better books are received eagerly. Thus, in economics, the American budget deficit is currently inescapable; and Joseph Granville’s forthcoming book, “The Warning,” which predicts a depression starting in 1987, is one of two or three nearly automatic assignments during the weeks ahead. Within medicine, does Rosenfeld have an equally compelling topic in his “Prolongevity II”?

No, he does not. The medical topic of the hour, if there is one, is not aging but AIDS. Aging is the very opposite of a new or urgent problem. And yet, as our population ages, the number of readers interested in new research on it is surely likely to be growing. Enter one half-count, then, against “Prolongevity” for not being headline material, but enter one to its credit for having a substantial and identifiable constituency.

But a further objection arises. Eternal youth . . . during the centuries, has any quest attracted more cranks? From Ponce de Leon to “Cocoon,” the laughable, lamentable parade of magic fountains, magic pools, miracle drugs and miracle diets is unbroken. Rosenfeld’s title has a faintly faddish sound. Sylvester Stallone, if he has accomplished nothing else, has rendered Roman numerals unsuitable for adult use. Is Rosenfeld’s “II” anything more than the latest float in the immortality parade?

Leaving Rosenfeld himself aside for the moment, his publisher is not one known for crank books, and the reputations of publishers do vary. Knopf, I am respectful enough to believe, would not have published Jan Rorvik’s “In His Own Image: The Cloning of a Man,” the scandal of a few years back. In areas in which no book review editor can trust his own judgment, an author is well served, at review time, by a publisher’s decades-long investment in intellectual integrity. Count one, therefore, courtesy of Knopf’s still healthy reputation, for “Prolongevity” as a serious book on a sometimes frivolous topic.

Rosenfeld himself is a science writer rather than a scientist, and certification for the former designation is a little looser than for the latter. However, as former science editor for Life and Saturday Review, he is at the top of his profession; he even holds an adjunct professorship in the department of human biological chemistry and genetics at the University of Texas. His credentials, in short, do not trouble; they reassure.

Granted then that “Prolongevity” seems eminently reviewable, is it the only new book on the subject? Is there no wholly new book that might be better than Rosenfeld’s? And given limited review space, should that book, if there is one, get the nod?

Carol Kahn’s “Beyond the Helix, DNA and the Quest for Longevity” (Times Books) is clearly a contender. Some readers might even find its more personalized, “60 Minutes” style more to their liking. Kahn’s is a lively book that tries to communicate the excitement of science. A typical chapter opens: “It was January 1979. In Laramie, Wyoming, Joan Smith-Sonneborn was keenly anticipating sharing with her colleagues the incredible results of her life-extension experiment. . . .” Where Rosenfeld talks about the research, Kahn talks about the researchers. She wants to carry the story of James Watson’s discovery forward in the manner of Watson’s own galloping “The Double Helix.”

Not to conceal personal prejudice, I generally prefer the research to the researchers. Both books may deserve review, but on balance Kahn’s does not displace Rosenfeld’s on its own terrain. The quarry of longevity is almost incidental, in her account, to the thrill of the chase. In Rosenfeld’s more sober account, the quarry--longevity itself--is always in view. And on this particular topic, a topic, crucially, in applied science, many readers will care more about the outcome than about the story.

All right, then, on to the next step: Who can review “Prolongevity II” for us? Often a semi-doubtful entry will win a review if a perfect reviewer comes instantly to mind. The goal, after all, is not abstract completeness or fairness--impossible anyway in our few pages--but interesting, literate reading of a Sunday morning. We have only a few qualified biomedical reviewers on our otherwise populous Rolodex. A couple of those we do have are already reviewing other books.

I decide to try a medical writer whose name I picked up some months ago when I persuaded a noted agent to talk through his client list with me. I phone this writer, who listens respectfully but declines. The book seems worthy enough, he says, but he prefers to confine his infrequent reviewing to science writing of the very highest literary quality: John McPhee, Lewis Thomas, nobody much below that level. Rosenfeld’s is just not a name that means much to him in literary terms. He suggests that I offer the assignment to a friend of his, a friend whose name, as it happens, means nothing to me.

And there it stood as of Aug. 10, 1985. I console myself that a book we should have reviewed last June when Knopf was publicizing it to bookstores is, after all, the second edition of a work that may well become a minor classic. Our review when we finally arrange it will help some and should make interesting reading. The absence of our review probably hasn’t hurt much.

The voices raised in the foregoing “panel discussion” about “Prolongevity II” include most of those usually heard when a nonfiction book is under consideration. (Fiction, poetry, children’s books and art books all raise different questions.) The nonfiction voices address, at least: the originality of the book, the timeliness of its topic, the importance of its topic to some identifiable readership, the reputation ty of the publisher, the credentials of the author, the style of the author, the strength of the book against competing new books on the same topic, and the availability of a qualified and engaging reviewer.

And how often do little one-mind panel discussions of this sort take place at The Book Review? When last The Times tried to keep track, we were receiving an annualized average of 100 books per working day, rising to a peak of 300 during the fall season, dropping below that during slower months of late spring and summer. That’s a thundering herd of books, and so I must ask the indulgence of readers of The Book Review if I now excuse myself from talking further to them and retire indefinitely to the shelves where the herd is penned--there to talk to myself about what Los Angeles may soon be reading.