The structure and genesis. of leukocytes, along with the different shapes as seen using micro-photographs is discussed and listed on the board. The main function of the white blood cells , phagocytosis of bacteria and virus particles as seen through photographs. Their function in antigen-antibody reactions to instill long term immunity to specific disease organisms will be discussed. The shape, genesis , and function of platelets will be outlined as a lead in to the process of blood clotting.