Wright's stain, 500x

The lymphocyte (red arrow) is a cell that is generally larger than a red blood cell and which contains a small amount of granular, basophilic cytoplasm. The nucleus is round to oval, sometimes indented, and occupies most of the cell. Normally only mature lymphocytes circulate in the blood. The black arrow indicates one of two nucleated erythrocytes (metarubricytes) found in this field. Note that the metarubricyte has a much redder cytoplasm due to its hemoglobin content, and that the nucleus is very dense as it is undergoing pyknosis (or apoptosis).