PIL IS CURRENTLY DEFINED BY THE AMERICAN BAR ASSOCIATION AS AN EFFORT TO PROVIDE LEGAL REPRESENTATION TO PREVIOUSLY UNREPRESENTED GROUPS AND INTERESTS. DISTINCTION BETWEEN PRIVATE AND PUBLIC INTEREST LAW DATES FROM THE 19TH CENTURY AND WAS ESPECIALLY INFLUENCED BY THE LEGAL DEFENSE AND EDUCATION FUND OF THE NATIONAL ASSOCIATION FOR THE ADVANCEMENT OF COLORED PEOPLE, AND THE AMERICAN CIVIL LIBERTIES UNION. GOVERNMENT EFFORTS SINCE THE LATE 1950'S HAVE FURTHER FOSTERED DEVELOPMENT OF PIL. RALPH NADER'S ORGANIZATIONS AND FOUNDATION-SUPPORTED PIL FIRMS EMERGED IN THE LATE 1960'S. THERE ARE CURRENTLY FEWER THAN 100 PIL FIRMS; SOME ARE AFFILIATES OF OTHER ORGANIZATIONS WHILE MOST ARE INDEPENDENT. THE TOTAL NONATTORNEY PROFESSIONALS ALSO NUMBER ABOUT 500. THE FIRMS' 1975 BUDGETS AVERAGED ABOUT $475,000. SOURCES OF FUNDS INCLUDED FOUNDATIONS (27 PERCENT), CONTRIBUTIONS (26.5 PERCENT), MEMBERSHIP DUES (20 PERCENT) AND OTHERS. IN CONTRAST TO TRADITIONAL LAW PRACTICE, PIL FIRMS' LAWYERS USUALLY ACTIVELY SOLICIT CLIENTS AND ORIGINATE CASES. ABOUT 60 PERCENT OF THEIR TIME IS SPENT ON LEGAL WORK; THE REMAINDER IS SPENT ON LEGISLATIVE WORK, INFORMATION DISSEMINATION, AND INTERNAL ADMINISTRATION. CASE EXAMPLES FROM ENVIRONMENTAL, CONSUMER, CIVIL LIBERTIES, AND OTHER SUBJECT AREAS ILLUSTRATE SUBSTANTIVE RESULTS ACHIEVED BY THESE FIRMS. DESPITE THEIR UNCERTAIN FINANCIAL FUTURE DUE TO DECLINING FOUNDATION FUNDING AND THE CONCOMITANT NEED TO FIND PERMANENT FUNDING SOURCES, PIL FIRMS AND PIL REPRESENT A PERMANENT FORM OF INSTITUTIONAL REFORM, SUBJECT TO CHANGE OVER TIME. FOOTNOTES INCLUDING REFERENCES ARE INCLUDED. (CFW)