The cytoplasm eventually becomes more eosinophilic, and the cell is called an orthochromatic erythroblast . This orthochromatic erythroblast will then extrude its nucleus and enter the circulation as a reticulocyte . Reticulocytes are so named because these cells contain reticular networks of polyribosomes. As reticulocytes loose their polyribosomes they become mature red blood cells. Examples of the developing cells are shown below.
Mature erythrocytes are visible in most pictures.
A pure field of mature erythrocytes can also be seen by clicking here . Students wishing further information may consider the following links . If you need more information, the best place on the internet to search is usually the National Library of Medicine .