The lymphocyte is typically the most numerous and most important of the agranulocytes. Structurally, lymphocytes can be identified in smears by their very high ratio of nucleus to cytoplasm. The cytoplasm is a thin band to one side of the nucleus, and is stained a dusky blue color. They are morphologically indistinguishable. To see a lymphocyte, click here.
Monocytes are the second type of agranulocyte, and the largest of the circulating formed elements.
A healthy monocyte will run anywhere from 16 to 25 microns in diameter, much larger than any other formed element. A monocyte can be seen if you click here. The ratio of nuclear material to cytoplasm is also less than in the lymphocyte. The final formed element to consider is the platelet , which, like the erythrocyte, isn't a cell at all. Like the erythrocyte, the platelet was once part of a cell, but in its maturation it loses its true cellularity.