The cells shown here are basophils and also represent different stages of maturation. The basophil at the left is relatively young and small.  The basophilic granules are variable in size and tend to obscure the morphology of the nucleus. Also, they are less plentiful than the granules seen in the eosinophil.  The appear donut-shaped. Two white cells, both granulocytes, are evident. One cell is a neutrophil (N), the other granulocyte is an eosinophil (E). However, at this magnification, the major distinction is in the staining of their cytoplasm. Higher magnification, as in the figures below, would allow for a more precise characterization of the cell type.
fine granules. The nucleus still exhibits a U shape, but lobulation (arrows) is becoming apparent with the constriction of the nucleus at several points. The neutrophil to the right shows greater maturity by virtue of its very distinctive lobulation. Here the lobules are connected by a very thin nuclear “bridge.” A very distinctive feature associated with the nucleus of this cell is the presence of a the Barr body (arrow), indicative of blood that has been drawn from a female.
eosinophil shown in the middle is larger and its nucleus is now distinctively bilobed. At one site, three distinct granules (arrows) are evident. Note their spherical shape and their relative uniform size. The eosinophil at the right is more mature in that it displays at least three lobes. By going through focus, the eosinophil granules often appear to “light up” due to their crystalline structure.
nucleus of the middle basophil appears to be bilobed, but the granules that lie over the nucleus, again tend to obscure the precise shape.  The basophil at the right is probably more mature. The granules almost entirely obscure the nuclear shape. A few blood platelets (arrowheads) are seen in several of the micrographs. Typically they appear as small, irregular shaped bodies.
PLATE 17 KEY E, eosinophil N, neutrophil
Lymphocytes, blood smear, human, Wright’s stain, 7–9m. A large lymphocyte is seen in the right panel. These cells may be as ×2,150. large as 16m. The lymphocyte in the middle panel is intermediate in size. The difference in lymphocyte size is attributable mostly to the amount of
The lymphocytes shown here vary in size, but each represents cytoplasm present. However, the nucleus also contributes to the size of the a mature cell. Circulating lymphocytes are usually described as cell, but to a lesser degree. In differential counts, lymphocyte size is small, medium, and large. A small lymphocyte is shown in the disregarded. Two platelets (arrows) are evident in the left panel.
left panel. Lymphocytes in this category range in size from
Monocytes, blood smear, human, Wright’s stain, ×2,150.
The white cells in these panels are mature monocytes. Their size ranges from approximately 13–20m, with the majority falling in the upper size range. The nucleus exhibits the most characteristic features of the monocyte, namely an indentation, which is sometimes so prominent that it exhibits a U shape as is evident in the right hand panel. The cytoplasm is very weakly basophilic. Small, azurophilic granules (lysosomes) are also characteristic of the cytoplasm and are similar to those seen in neutrophils. Platelets (arrows) are present in the left and middle panels.
Bone marrow smear, human, Giemsa, ×180.