Most of the basic characteristics of British medical practice were apparent in embryonic form at the time of the Medical Act of 1858 and were clearly in existence by 1900. These patterns include the development of the present system of undergraduate education and registration and of postgraduate ex­ aminations; the relative functions of the professional bodies and the uni­ versities; the operation of the referral system between general practitioner and specialist; and the staffing structure of British hospitals. They thus antedate the major influence on modern medicine-the vast and sudden strides in medical research that compelled a rapid growth of specialization, and the emergence of the National Health Service-and a knowledge of their origins is necessary to understand the structure and operation of cur­ rent medical practice.