It has been many years since the back office was graced by Boswell the Bookstore Dog. The bay windows hold a best-seller list of unliterary sidelines such as hand-turned bowls, teddy bears and boxes of garlic paste.

And, sad to say, commercial pressures have reached far into the countryside, corrupting the once-pure stock with a rack of silly romances about passion and debutantes.

Yet the Cricket Book Shop, tucked along with the Ashton Post Office (ZIP code 20861) in an old, gabled, shingle-and-moss-roofed ice cream parlor, 20 miles north of Washington, still retains the essence of a country bookstore.

"When people come in looking for a book about cancer or the death of a child, you know they aren't just looking for a book," said Mary Miller.

Miller, a peppery woman and mother of five, bought the first book ever sold by the Cricket, in 1969, and nine years later acquired a half interest in the Cricket itself.

Miller and her partner, Mary Jo Wilson, along with their four part-time employes, know most of their customers' names and bookly inclinations.

A big city bookstore is like a supermarket; a country bookshop is a much more intimate matter.

The proprietors hang the watercolors of grade school Rembrandts, and wonder what's amiss with Cindy Thomas if she doesn't pop by on her regular Thursday night visit. They special-order books. (Attention Burton Johnson: pick up your three copies of "Forever Thin.") Old people get a 10 percent discount, an offer that draws the Great Books Club from nearby Leisure World.

Leisure World resident George Porter stopped by last week on a club errand to pick up 12 copies of "Anatomy of Revolution." (Attention FBI . . . ).

Running a country bookstore means you have to produce when a customer asks for "something neat with a goat theme."

It means letting mothers nurse their babies by the microfiche machine in the back.

At trade conventions, it means that Wilson and Miller pick books with their friends in mind.

They may choose a few titles in the category of Eastern philosophy, for instance, on the hunch that the books might appeal to Kimberly St. Clair, who goes for Zen so much she named her baby Zen.

In a sense, the Cricket's stock, weighted toward fact not fancy, is a reflection of the town it serves. Solar power books are big. The numerous weavers and woolgatherers in the area seem to grab the potholders embroidered with sheep, passing up the ones with pigs.

Miller, with an M.A. in theology, has given up trying to foist obscure German theologians on the local populace: not Ashton's cup of tea.

It's rare you'll ever find more than one or two copies of an economics book at the shop because hardly anybody but Mr. Boyer buys the stuff.

The stock at the Cricket, which has a mailing list of 1,500 people, does range with catholic breadth.

There is a generous shelf of poetry (always a good measure of a bookstore's soul), philosophy, Maryland folklore, politics, history, and many cookbooks, including the area's favorite, "The Enchanted Broccoli Forest." Vegetarian cookbooks outsell French cookbooks. There are Cliff Notes for laggard scholars at nearby Sherwood High School, and a wall of durable, drool-resistant books for the new generation of readers just beginning to grapple with the headaches and delights of English.

The picture of Ashton that emerges from its bookstore is infinitely more complex than the impression the town makes on motorists barreling up New Hampshire Avenue in upper Montgomery County.

The bookstore reveals its hidden life; otherwise Ashton is just a faceless intersection with a bank, a High's, two gas stations, a flower emporium and the Cricket.

Set back from the highway with a bluestone parking lot and a sign planted in a patch of tiger lilies, the shop appears out of the woodlots and vegetable stands as an improbable find.

Imagine stumbling upon Edmund Wilson in a checkers tournament.

At one end of the gabled building, postmaster Richard Farquhar, 65, has been working more than a quarter of a century.

He still sorts the mail by hand and eschews the sponge, wetting stamps with his tongue--an incomparable hallmark of small-town life.

"Are you Richard Farquhar?" a visitor asked. "What's left of him," he said.

Between the P.O. and the Cricket is a billboard where townspeople advertise free kittens, piano lessons, child care and where Joseph W. Pastori let the world know he is a Counselor At Law.

And then the bookshop: the front door swings beside a cheerful, hand-carved sign of a Jiminy Cricket look alike, wearing a green bowler and sitting on a couple of Gutenberg Bible-sized books, tracing a line of type on a folio with one of his insectile limbs.

The atmosphere inside the shop is redolent with the studious scent of freshly minted books. Baroque music plays softly in the background.

Until a few years ago, the Cricket was located across the street.

The store was founded by Nan Yarnall, who raised Boswell the Bookstore Dog, kept out romance novels and lost money every year. The Cricket sprang from an opportunity in Ashton real estate market and the dream of running a bookstore Yarnall had harbored since she was a little girl.

The name "came out of the blue," she said.

"I always liked crickets. They're friendly little creatures. Then somebody told me they eat books." Yarnall, who now works in a library in Baltimore, kept the shop open from 10 a.m. to 10 p.m., seven days a week, and often stayed at work past 2 a.m. tending business. She worked herself into bad health and was forced to sell the store in 1976. Two years later Mary Jo Wilson took on Mary Miller as a partner.

The two women moved the Cricket a few years ago, when the Cosmic View, an organic fertilizer concern, vacated the premises. "People still come in looking for fertilizer," Miller said.

Thanks to the new location, which for some reason is more visible than the old one, and to the gift items strewn among the books, the Cricket has begun to turn a profit.

But the women have no plans to change their course, or the Cricket's countryish ways.

"There's a children's book called 'This Is How We Live in Town,' " said Mary Miller, pointing to a big bright book in the children's section. "We sold the one called 'This is How We Live in the Country.' No one wants the one about the city."