[alpha]. The spleen 84 [beta]. The lymphatic glands 100 [gamma]. The bone-marrow 105 III. ON THE DEMONSTRATION OF THE CELL-GRANULES, AND THEIR SIGNIFICANCE 121 History of the investigation of the granules 121 Since Ehrlich. 123 Methods of demonstration 124 Vital staining of granules 124 The Bioblast theory (Altmann) 128 The granules as metabolic products of the cells (Ehrlich) 130 Secretory processes in granulated cells 134 IV. LEUCOCYTOSIS 138 Biological importance of leucocytosis 138 Morphology of leucocytosis 142 [alpha]. 1. Polynuclear neutrophil leucocytosis 143 Definition 143 Clinical occurrence 144 Origin 144 [alpha]. 2. Polynuclear eosinophil leucocytosis, including the mast cells 148 Definition 149 Clinical occurrence 150 Origin 154 [beta]. Leukaemia ("mixed leucocytosis") 167 Lymphatic leukaemia 170 Myelogenous leukaemia 171 Morphological character 187 Origin 187 V. LEUKOPENIA 188 The blood platelets. The haemoconiae 190 INDEX TO LITERATURE 195 INDEX 209 PLATES INTRODUCTION. DEFINITION OF ANAEMIA. CLINICAL METHODS OF INVESTIGATION OF THE BLOOD. In practical medicine the term "anaemia" has not quite the restricted sense that scientific investigation gives it. The former regards certain striking symptoms as characteristic of the anaemic condition; pallor of the skin, a diminution of the normal redness of the mucous membranes of the eyes, lips, mouth, and pharynx. From the presence of these phenomena anaemia is diagnosed, and according to their greater or less intensity, conclusions are also drawn as to the degree of the poverty of the blood. It is evident from the first that a definition based on such a frequent and elementary chain of symptoms will bring into line much that is unconnected, and will perhaps omit what it should logically include. Indeed a number of obscurities and contradictions is to be ascribed to this circumstance.