Across America, millions of children arrive at school in the morning hungry. And teachers know what that means: listless children who don't pay attention, who sometimes fall asleep at their desks, who complain about headaches, dizziness and stomach aches. Hungry children simply cannot function in the classroom as effectively as those who get their nourishment.

One seven-year-old summed up the problem with touching simplicity: "I get a headache that hurts when I don't eat in the morning."

Congress created a nationwide school breakfast program more than a decade ago. Implementation was left to the Agriculture Department, but the department's lackadaisical bureaucrats would rather pass out subsidies to farmers than food to poor youngsters.

This attitude is exemplified by an Agriculture official who was questioned about the breakfast program during a legal proceeding. He was asked for a "reasonable" estimate of how long it would take to make breakfast available in every school.

"I suppose," he said, "two generations ought to come close to reflecting the congressional intent." The flabber gasted attorney demanded. "Could it be done any faster than, say 50 years from now?" Replied the bureaucrat: "I don't know. I can't comment on that. I don't know."

Thus 11 years after the Agriculture Department was supposed to start providing schoolchildren with subsidized breakfasts, only 18 per cent of the nation's schools offer a breakfast program. Parents and teachers alike have tried to disentangle the feeding of children from this bureaucratic snarl. Now the Food Research and Action Center, dedicated to waging war against hunger, is taking the issue to court.

The group is preparing a class-action lawsuit against the Agriculture Department for neglecting the breakfast program. The evidence has already been extracted from officials in sworn depositions. We have examined some of the findings, which have been held back from the press. Here are some startling highlights:

Some 14 million children are eligible for breakfasts free of charge or at reduced prices. Yet the breakfasts were available only to five per cent of these needy children in 1971, less than 10 per cent in 1972. At the present rate of increase, it would take 46 years to provide breakfast to every improverished child. Yet Agriculture officials swore this wasn't an unreasonable timetable.

The Agriculture Department hasn't yet established uniform standards for determining which schools are eligible for the subsidized breakfast. Some states, therefore, have decided all their nonparticipating schools are eligible, while others insist that none of their schools needs the program. Incredibly, Phillips Exeter Academy, one of the nation's wealthiest private schools, offers the government-sponsored breakfasts. Yet Mississippi has no breakfast program for 236 schools, which have a 90 per cent eligibility average.

Because the program was still failing to meet its objectives in 1971. Congress decided to require every state to submit a plan detailing its intentions. The purpose was to make sure the states made the necessary preparations before any federal funds were released for child nutrition. Yet Agriculture officials have approved state plans that are wholly inadequate. Of 330 plans approved between 1972 and 1977, only 24 contained lists of school districts that intended to offer breakfasts to more poor children.

The Agriculture Department hasn't bothered to withhold funds from states for submitting poor plans, nor has any action been taken against a state for failing to achieve its objectives. Some plans have been approved, in fact, even though they stated outright that the programs would not be expanded.

The failure of states to expand the program to cover thousands of low-income children prodded Congress into action. The breakfast program, lawmakers decided must be offered in all schools whose student bodies contain 25 per cent low-income children. Agriculture officials, however, have ignored this congressional mandate and have refused to require the states to comply.