Tumors of the Breast.

as systemic lupus erythematosus and malignant melanoma. It is, however, difficult to write a good textbook of immunology for medical students. This is in part because those not immersed in the field lack the knowledge to write it, while those with detailed knowledge of immunology often lack a feeling for the needs of the medical student and the motivation to write a didactic text. Moreover, the temptation is to write a book which is too detailed and is directed towards the fundamental rather than the clinical aspects of the subject. Dr Turk has succeeded in writing a clear and fairly dogmatic account of immunology which covers most of the field and is not confined to his own special interests. The scope of the book is well described in the preface. He states that a textbook of immunology 'should discuss the immunological concepts underlying disease processes rather than the principles behind laboratory tests' and correctly emphasizes that books of multiple authorship often present either a 'confusi of opinions' or omit important topics. The bibliography is a valuable feature of the book and should serve to entice research-minded students into laboratory work. The outline offundamental immunology deals somewhat cursorily with the involvement of both thymusand bone marrow-derived cells in immune responses, and the existence of high and low tolerance might have been emphasized because of its relevance to the possibility of deliberately inducing tolerance with transplantation antigens in humans. The value of the book would be increased if the principles and significance of