Max Schultze and the living, moving, phagocytosing leucocytes: 1865.

In his study, published in 1865,' of living human leucocytes examined at body temperature with the highest powers of the microscope then available, Schultze described for the first time four different types of leucocyte corresponding to what are now recognized as the lymphocyte, the monocyte, the neutrophil polymorphonuclear leucocyte, and the eosinophil leucocyte. The detail and precision of his descriptions of the movement of cells, and particularly his description of the intracellular granules and of the phagocytosis of a variety of particles, and their intracellular movements, are, to one who has examined these happenings with modern phase contrast microscopes, truly astonishing.2 Yet his findings had little influence on current thought regarding the function of the phagocytes in inflammation. It was to be almost another twenty years before Ehrlich developed his staining methods which greatly simplified the recognition of the different types of leucocytes, and before Metchnikoff convincingly demonstrated the importance of phagocytosis in defence against bacterial disease. The reasons for this are uncertain. The title of the paper is singularly uninformative. 'Ein heizbarer Objecttisch und seine Verwendung bei Untersuchungen des Blutes', i.e. 'The heated stage and its use in the investigation of the blood'. It gives no indication of the wealth