For barely an hour each morning, they fan out over the teeming streets of Bombay's commercial center, precariously balancing long wooden trays filled with aluminum cylinders on their heads and zig-zagging through madcap traffic before vanishing as abruptly as they appear.

Visitors shake their head in puzzlement, wondering what the strangely inscribed metal containers hold and where their energetic and fleet-footed carriers disappear to after their brief but stunning appearance.

They are Bombay's dabbawallas, runners in an ingenious relay delivery system that each day carries more than 100,000 home-cooked hot lunches up to 40 miles from house to office and almost never results in a mixup.

Sambaji Medge, one of the 2,000 dabbawallas who pour out of Victoria and Churchgate railway stations each morning, claimed that in 14 years he has never lost a dabba, or three-tiered lunch pail, although the laughter of his coworkers suggested that Medge's boast may have been exaggerated.

Nonetheless, the dabbawalla system -- devised and run by illiterate peasants -- works as if it were orchestrated by computer and managed by efficiency experts. Changing hands at least four times before reaching its destination, the hot lunch completes its journey unerringly largely because of teamwork honed by generations of dabbawallas whose family trade is a source of pride, albeit providing meager financial reward.

The odyssey of an average tiffin -- as the hot lunches are called -- normally begins in Bombay's sprawling suburbs at 10 a.m. when, long after her husband has commuted by train to work, a housewife will fill the stacked container with mutton curry, rice, vegetables and chapatis -- thin flatbread -- and hand it over to the first dabbawalla in the relay.

After collecting 35 to 40 tiffins, the dabbawalla hands them to a colleague who shuttles the tray by bicycle to the suburban railway station and gives it to another dabbawalla, who picks out the tiffins bound for one of Bombay's two main terminals and boards the train.

On arrival in the city, the tiffin is again sorted according to its destination markings and handed to another dabbawalla, who runs it to its designated office. The same process in reverse assures that the empty container is returned to its home after the lunch hour.

Since most dabbawallas are illiterate, the relay points along the route are indicated by crude symbols -- a swastika, for example, connoting the suburban station at Dadar, and a yellow stripe signifying Victoria station in Bombay. Since apprentice dabbawallas are usually trained by their fathers, the symbols are passed down through generations and are uniform among all dabbawallas.

The operation is supervised by contractors called mucadams, who normally employ three or four "servants" and who themselves answer to a dabbawalla guild, the Bombay Tiffinbox Suppliers Association.

How a tiffin makes its way to its proper destination amid the chaos of Churchgate station in the morning remains a puzzle to an outsider.

Tens of thousands of seemingly identical lunch pails suddenly come together in the swarming concourse of the station and in a frenzy of loudly shouting dabbawallas are shuffled like a deck of cards with blinding speed and transferred to the six-foot trays before suddenly disappearing into the crowd-filled sidewalks.

Containers rolling across the marble floor and an occasional demonstrative argument add to the bedlam, but by noon the hot lunches are all gone, and are making their way up flights of stairs to offices throughout central Bombay.

"It's hard work, sahib. A dabbawalla gets very tired when he becomes 30 years old," said Medge, who should know, because he is 30 and looks tired.

A dabbawalla all his adult life, Medge recently spent his life's savings of 6,000 rupees (about $600) to buy out a dabbawalla contractor and become a mucadam overseeing three "servants."

The lunch delivery service costs an office worker about $3 a month, and a hard-working dabbawalla can make about $40 a month. Most of the dabbawallas come from the Poona area, about a four-hour train ride from Bombay.

Medge said that if a tiffin is lost, or is stolen by one of the gangs of dabba thieves who ply the streets of Bombay, the owner is paid half the price of a new lunch pail.

But pride also plays a part in the dabbawallas' determination to get the hot lunches to their destination, and it is not unusual for a dabbawalla to get off a stalled train and walk the last mile or so with an 80-pound load of lunch pails on his head to keep his rendezvous at the next relay point.

"My father and his father were good dabbawallas. I'm not making mistakes," Medge said.

The origins of the dabbawalla system are obscure, but it is said that at the turn of the century a British gentleman started it by having his bearer deliver his hot lunch to his office; his friends followed suit. The servants, according to the legend, organized a pool to simplify their task and refined it until it became the famous dabbawalla network.

As long as Bombay businessmen and bureaucrats continue to favor their wives' home cooking for lunch -- and look forward to the occasional personal notes slipped into the tiffins -- the dabbawalla is likely to remain an institution in India's second-largest city.

For Medge, however, the end of his daily race against time and the pandemonium of sorting out dabbas may be near.

"I have to slow down. I'm getting tired," he said as he hoisted 35 lunch pails on top of his head and trundled off on his rounds.