(2) Nucleus. The nucleus is dark, round or oval, and smaller than the
prorubricyte nucleus. The chromatin material is found in dense, irregular clumps.
Nucleoli are not present.
(3) Cytoplasm. The cytoplasm is more abundant than in the precursor cells.
It is blue-pink (polychromatic), the pink resulting from the first visible appearance of
hemoglobin. Cytoplasmic granules are absent.
Figure 4-1d. Erythrocytes series: Metrarubricyte.
Size. Seven to 10 microns in diameter.
(2) Nucleus. This cell has a pyknotic nucleus (a homogeneous blue-black
mass with no structure) that is round. This is the main difference between the rubricyte
and the metarubricyte.
Cytoplasm. The cytoplasm is abundant, bluish-buff to buff pink.
e. Reticulocyte (diffusely basophilic erythrocyte).
Figure 4-1e. Erythrocytes series: Reticulocyte.
Size. Seven to 9 microns in diameter.
Nucleus. The nucleus is absent.