A WHOLE SHELF in the library of my elementary school held a series of orange-colored biographies: Clara Barton: Girl Nurse, Thomas Alva Edison: Boy Inventor, and so forth. Fungus Fighters reminds me of those books; instead of its dreadful title, it might have been called Elizabeth Hazen and Rachel Brown: Girl Scientists. In 1950, Hazen and Brown discovered the first antibiotic that could be used to combat fungal disease in human beings. The two were then 65 and 52 respectively, but the director of the New York State Division of Laboratories and Research (where they worked and after which the drug, Nystatin, was named) still called them "the girls." This appalling fact is reported twice, without comment, in Fungus Fighters, a shallow account of Hazen, Brown and their discovery.

When Hazen graduated from college in Mississippi, she received two documents: a bachelor's degree and a certificate in dressmaking. With extraordinary diligence and spunk, she managed to become a professional microbiologist, not a seamstress. Brown, a New Englander with a similar spirit, became a chemist. After Hazen conceived the project of searching soil samples for an antifungal agent (following the example of Selamn Waksman, discoverer of Streptomycin), she and Brown, who worked elsewhere in the division, were introduced and encouraged by their boss to pursue the matter, as long as their service work for the laboratory did not suffer. It must be said in his favor that when they succeeded, the boss evidently made no attempt to rob "the girls" of credit for their discovery. Other women in science have been less fortunate.

Hazen and Brown were successful, but it stretches a point to call what they did "science." Like most of the women in their generation who went into a scientific field, they were trained to be diligent, meticulous technicians and were made to spend a professional lifetime as "good girls." This generation was, by and large, kept out of universities. Instead, they worked in service laboratories, as Brown and Hazen did; taught in women's colleges; or served as research assistants to male professors. The work that Hazen and Brown did was neither imaginative nor original; it was methodical, painstaking, and somewhat lucky. They never dropped a stitch, and they were, after a fashion, rewarded. But they were confined to a professional status and a role in science that robbed them of the opportunity to strike out on their own, to try changing the way we think about the world (which is what science is really about). Their willingness to do what they did, and their success, were nevertheless important because they began the breaking of barriers without, somehow, letting their own hearts get broken in the process.

Anna Brito is the pseudonym for a living scientist, about whom June Goodfield has written in An Imagined World. At 41, Anna Brito, who was trained as a physician in her native Portugal, is working at a major research center in New York. She has made important contributions in her field of immunology and now appears to be in the process of bringing about a small revolution in it.

Six years ago, Anna Brito agreed to let Goodfield, an historian of science, observe her at work. At the time, the scientist was just beginning to pose some half-formed questions about why a class of infection-fighting cells disappears from the blood of patients with certain diseases. In seeking the answers, she had developed a major hypothesis about the way cells of the immune system are coordinated to do their work. The collaboration was a courageous undertaking: the record might have merely embarrassed the scientist and frustrated the chronicler. In the event, it was an enormously fertile epoch for them both.

In writing her book, as well as conceiving it, Goodfield has taken chances. She has chosen not to foreshadow the course that Anna Brito's ideas would take. As a result, the reader founders when the scientist is uncertain and feels some of the excitement when things begin falling into place. But this strategy does not always work. The questions Anna Brito asked herself are not as sharply laid out as they could be, and background information is sometimes presented in a jumpy, back-and-forth narrative. Immunology is a difficult field, full of elusive concepts and myriad tiny facts. Someone who has only a nodding acquaintance with the subject, as I do, may be perplexed by the explanations in this book; a neophyte could get lost. Unfortunately, few illustrations are used, and those poorly. Anna Brito's mind appears to be highly visual (whereas, one suspects, Goodfield's is not), and the reader could have come much closer to her ways of thinking with a richer set of pictures. I resorted to a couple of scientific articles to be sure I understood what was happening.

Goodfield has also chosen to publish her book before the denouement of Brito's work. We cannot yet be certain how her scientific peers will receive her findings. This was a risky decision; although the story gains immediacy, it loses perspective. The narrative is intense and inward, and almost without humor; the focus is unpredictable and selective. Perhaps too much attention is paid to the scientific problem and too little to Brito's circumstances: she often seems isolated in this account, and yet it is clear that she is very well connected in the scientific world. A better balance between the subjective and objective aspects of this scientist's career would have made a better book.

Be that as it may, reading An Imagined World is an exhilarating experience. Anna Brito clearly faces many of the same prejudices about and resistances to a woman in science that kept Hazen and Brown in check. But the adversity is external. Anna Brito has a free scientific spirit. She is not a "good girl" but an enfant terrible in the happiest and most productive sense of the term.