eosinophil

a variety of white blood cell distinguished by the presence in its cytoplasm of coarse granules that stain orange-red with ROMANOWSKY STAINS . The function of the eosinophil is poorly understood, but it is capable of ingesting foreign particles, is present in large numbers in lining or covering surfaces within the body, is involved in allergic responses, and may be involved in host defence against parasites. There are normally 40-400 x 106 eosinophils per litre of blood.