BOSTON -- This is a story that begins with white male rats. The subject is science and sex. It turns out that most of the basic research that teaches us what is good and bad for human beings begins with rodents of the male persuasion. Their female counterparts are usually excluded because of what might be called ''raging hormonal imbalance.'' Their female physiology is more complex.

I didn't come across this information through personal experience. I have never seen a female rodent with PMS, let alone hot flashes. Nor have I ever before worried that they were denied equal employment opportunities as research subjects.

Rather, the tale of the white male rat was reiterated at the congressional hearings of the House subcommittee on health and the environment this week. These creatures were a small if furry part of the larger saga. In research, femalehumans are also excluded from most studies done on ''people.''

The pills women swallow, the diets that we follow and the exercises we do -- the health plan that is prescribed for us -- are for the most part based on research done on a thoroughly male model. Remember the cholesterol study? Its 4,000 subjects were men. Remember the smoking study? The 15,000 subjects were men. How about the aspirin study? Its 22,000 doctors were all male.

The end result is that women with heart disease -- the No. 1 killer of women -- and all sorts of ills are by and large treated as if they were men. And while this experience might be refreshing in a paycheck, it could be dangerous in a checkup.

The hearings that brought the tale of the neglected females of two species to the public consciousness were called because of a government study pushed by the congressional women's caucus. The study showed that the National Institutes of Health had failed to fulfill its own four-year-old policy to include women in clinical trials. The scientists who planned, proposed and funded research had paid little more attention to it than a smoker pays to a warning on a cigarette pack.

But it turns out that the exclusion of women as subjects for research is only one piece of a profoundly skewed research program. Not only are men studied more, so are their health problems. Diseases like ovarian cancer and osteoporosis remain second-class subjects. Even breast cancer, which kills 40,000 women a year, gets only $17 million for basic research.

All in all, about 13 percent of NIH's $5.7 billion budget goes to study the health risks of the half of the population that is female. While every woman in America will go through menopause, hormone treatment has little priority in terms of federal dollars. While every woman ages, the latest study -- entitled ''Normal Human Aging'' -- has no data about women at all.

''I've had a theory that you fund what you fear,'' says Rep. Patricia Schroeder (D-Colo.), who along with Reps. Olympia Snowe (R-Maine) and Henry Waxman (D-Calif.) has kept a spotlight on this issue. ''When you have a male-dominated group of researchers, they are more worried about prostate cancer than breast cancer.''

The fund-what-you-fear bias in health research goes straight through the medical system. After all, who decides what we should study, what is important and who is important? The dearth of female researchers, female reviewers, female doctors and female administrators at NIH has directly resulted in a dearth of research on women's health issues.

But conversely, the rise of women in medical and policy-making positions in the rest of the world has put these issues in the public eye. This summer, the congressional women's caucus will be presenting a health package that calls for more research.

In fairness, medical science is not all that different from any other business in America that is just beginning to adjust to women. There is the dual notion that you can either treat women just like men or exclude them altogether.

According to the rat theory, many researchers lament that including women with all their peculiar plumbing is too complicated and too expensive. But in the long run, research that is only valid for half the human species is no bargain.