White blood cells engulf bacteria. Coloured trans- mission electron micrograph (TEM) of a section through two polymorph white blood cells (blue) engulfing Bacillus cereus bacteria (magenta). These soil bacteria are a cause of human food poisoning. During phagocytosis the polymorphs (polymorphonuclear granulocytes) capture and then digest foreign particles or, as here, bacteria cells. Polymorphs are part of the immune system that protects the body from invading organisms. Magnification: x15,000 at 6x7cm size. x50,000 at 7.5x9.5"~LANDSCAPE"