A very high power (oil immersion 700X) micrograph of a stained blood smear showing an idiopathic leukocytosis. The reddish material consists of clumped red blood cells. The larger purple/pink cells are the white blood cells. A variety of white blood cells can be seen from the larger very abnormal immature cells to the smaller normal segmented neutrophils. This patient's blood picture returned to normal in a few weeks. There are various known and unknown causes for this condition which ususally resoves on its own. Magnification 700x oil immersion when printed at 10 cm.