White blood cells (WBCs, leukocytes) are nucleated cells produced from bone marrow; they have a role in body immunity. They form the first line of defense of the body against invading microorganisms. White blood cells are classified either as polymorphonuclear leucocytes (or granulocytes) or as mononuclear cells. Granulocytes are further divided into three subtypes, Neutrophils, eosinophils, and basophils. Mononuclear cells indicate both lymphocytes and monocytes. The Book reviews the production, morphology, distribution and kinetics, functions, non-neoplastic disorders, and inherited and...