Today's mini been is here! Leucocytes - Types and Functions Leucocytes are produced in the bone marrow by hematopoietic-stem cells, which differentiate into either lymphoid or myeloid progenitor cells. Leucocytes come out of the bone marrow and become part of the innate immunity. There are three types of leucocytes based on staining. Cells that do not stain, with the polymorphonuclear shape, are neutrophils. Cells that stain blue are mast cells and basophils. Eosinophils stain red. These cells a