They're as English as cucumber sandwiches and there is one a buttered scone's throw from practically anywhere in the British Isles.

When Marks & Spencer, the department store chain that last fall celebrated 100 triumphal years of retailing, last counted, there were 264 stores in the United Kingdom, 43 of them in the Greater London area. They serve 14 million to 15 million customers a week -- among them certain thrift-obsessed foreigners who, it is rumored, go straight from the airport to the nearest M & S and straight back to the airport with new-bought suitcases stuffed with bed linens, cashmere sweaters, tweed jackets and silk underwear.

Home-grown shoppers average five purchases each per trip and account each week for a million chickens sold in the stores' "food halls" and a staggering quantity of fish. Marks & Spencer is Britain's preeminent fishmonger (one of a number of areas in which it claims title to "Britain's biggest").

Not bad, all in all, for an enterprise that began on a moveable trestle table at the end of 1884, when an immigrant Jewish peddler who spoke no English set up his wares in the provincial Yorkshire city of Leeds.

Michael Marks, formerly of Grodno in what was then known as Russian Poland, began with a motley collection of kitchen wear, needles and threads, sheet music and haberdashery, and a genius for retailing. "Don't Ask the Price," said the sign on his table, "It's a Penny." There was no bargaining. Stock was clearly displayed. Customers were welcome to handle each item. And business thrived.

In 1893, Marks opened his first shop, which he called a penny bazaar, in Manchester, painting his penny slogan in scarlet on the store front. A year later he took into partnership a friend, Thomas Spencer, who had considerable bookkeeping experience and -- equally important -- a native command of English. By 1901, Marks was the proprietor of half a dozen market stalls in addition to the Manchester penny shop and, at that point, the Spencer name was added to the enterprise. It was established as a limited company in 1903.

Soon after, Spencer retired to a life of ease as a gentleman farmer, ending direct Spencer connection with the firm's management. It was a short retirement; he died in 1905, and he was not long survived by his partner. Michael Marks died suddenly at the age of 48, in 1907, a year when profits added up to 8,868 pounds and the M & S shareholders collected a 20 percent dividend.

Marks & Spencer has made money -- pots and pots of it -- ever since, even in the deepest years of the depression.

Canonization is customarily left to the church. In the case of Michael Marks, it was conferred in the board room. The patriarch is enshrined today in every item sold by M & S. From candy bars through orchid corsages to down quilts, they are all trademarked "St. Michael." He is the only saint among all the generations of Markses, but lords abound.

Michael Marks' son, Simon, led the way. Knighted in 1944, he became Lord Marks in 1961. His boyhood friend and double brother-in-law, Israel Sieff (they married one another's sisters), was named chairman of the company after Simon's death and later became the first Lord Sieff. He was followed as chairman by his son, Marcus, Michael Marks' grandson, who is the present Lord Sieff of Brimpton.

In addition to all this lordship, there is a Marks & Spencer coat of arms. In this, described by Asa Briggs -- Lord Briggs, as it happens -- in a souvenir centenary history of M & S that was presented last year to each employe, active and retired, "a lion, representing England, and an owl, representing wisdom, support a symbol of the Archangel Michael. A pair of golden scales portrays justice (and fair trading), white roses represent Yorkshire, where Michael Marks had his first stall, a ladder (from Jacob's dream) is a sign of the aspiration and will to improve, and a horn of plenty stands for the plenitude of goods sold by the company. Beneath the crest is the company's motto, 'Strive, Probe, Apply.' "

If "The Guinness Book of World Records" is taken as the guide, the store at Marble Arch, in the tourist heart of London, strives harder; it holds the world's record for retail sales per square meter, according to Guinness.

Marks & Spencer is famous both for quality and price: Shetland pullovers were recently priced at 12 pounds ($14.88 at the current exchange rate of $1.24 to the pound), pure wool tweed jackets at under 50 pounds, cashmere sweaters at less than 55 pounds and silk lingerie cost little more than synthetics.

Price is not the only reason to seek out the nearest Marks & Spencer on a trip to the U.K. While there are also 61 stores in Canada and a number in Paris, Rome, Antwerp and Brussels, on home ground M & S is as dottily British as a collective entity can get. It maintains a phenomenally liberal exchange policy: Any M & S purchase can be returned to any store regardless of where it was bought. But M & S has no changing rooms and no customer bathrooms where a determined shopper might wriggle into a skirt or try on a pair of trousers.

The management at Marks & Spencer is legendary, however, for its generosity to its employes, for whom it provides innumerable benefits including chiropodists and hairdressers, full meals for pennies, lengthy maternity leave and any number of shiningly clean and beautifully appointed bathrooms. And it gives 2 million pounds to projects aiding the aged, the sick and the mentally and physically handicapped every year. For the centenary, this was raised to 3.4 million pounds and augmented by an unsolicited 500,000 pounds contributed by the employes.

In keeping with these philanthropic leanings, it is no wonder that handicapped shoppers (or those suddenly stricken) may approach any salesperson and be escorted to an employe bathroom. The rest of the clientele either tries on its new purchases at home or, it is whispered, walks determinedly to the nearest department store and finds the bathroom.

In partial mitigation for this discrimination against the remainder of us, however, it should be conceded that M & S has gone American retailers one better in some areas. At lunch hour, when the aisles can be wall-to-wall customers, extra cash registers are wheeled into place to speed the check-out process. The ratio of sales staff to what the British call "backstage" help is seen in this country only in the most exclusive stores.

While M & S is a self-service store, polite, uniformed sales clerks stand ready to help. Display counters are angled to soften and divide space, and items are hung high so shoppers can make their way across a crowded floor without losing sight of their destination. Because all goods are made not simply for M & S but also under its exacting eye, it is possible to find matches between, say, tennis shorts and windbreakers or sweatpants and running shoes. This year's colors are particularly vivid, and pinks and turquoises are moving so fast that the manager of the biggest M & S, at Oxford Street in London, says with delight that "customers keep buying up all the nice colors and messing up the displays."

Suits -- men's and women's alike -- are also sold at M & S as separates, enabling hard-to-fit customers to choose a jacket in one size and trousers or skirt in another. Men's pure wool pin-striped business suits start at 99 pounds 50 pence, about half the price of equivalent suits elsewhere. And, like 90 percent of everything M & S sells, they are British-made.

Price aside, it is this patriotism that has done the most for the image of the chain in British eyes. M & S has just won the Queen's Award for Exports -- foreign sales totalled 84 million pounds, up nearly 24 percent, last year -- and it is one place where you can be sure the shoes don't come from Portugal and fantasize that the undies were sewn by British mums.

A by-product of the Buy British bent of M & S is its siren call to foreign investment in U.K. plants. One of this year's runaway successes is a packaged bouquet of five pairs of socks in the exact shades of the current bestselling lamb's wool pullovers -- turquoise, sky blue, white, tomato red and canary yellow -- at 4 pounds 75 pence. The Israeli-made socks sold so well, that their manufacturers opened a factory in England.

In addition to sportswear and British woolens, Americans are finding bargains at M & S in offbeat items like print covers for down and feather duvets at under 25 pounds (there are bed linens to match). Silk ties are 5 and 6 pounds.

But a visit to a "food hall," the superdupermarket where all those chickens are sold, is a tourist must.

Here you will find an enormous stock of carryout items, including a vast array of breads and rolls baked to M & S' exacting specifications and enough cheeses, wines and delicatessen items for a ducal picnic. To go with it all, store managers highly recommend a wine labeled only "French Dry White Wine from the Anjou." There are good teas, of course; and having succumbed to the tea bag, the British now make coffee bags. Avoid them. There is good news for chocoholics, though, in boxes of St. Michael's chocolates, reportedly giving Cadbury a run for its money.

Before you buy, however, check your wallet for cash or pound traveler's checks. Unlike most British stores, Marks & Spencer does not accept credit cards. If your American bank has a British branch or correspondent, you will be allowed to write a check. M & S itself is in the process of issuing its own store credit card. There were more than 400,000 applications in the first month, the largest number ever reported in the United Kingdom. Or possibly anywhere else.