1. With the aid of supravital studies and dark-field illumination, "motile" erythrocytes (capable of self initiated amoeboid-like change in form and, in some cases, movement from place to place) may be found in the peripheral blood of cases of anemia, particularly those of the macrocytic variety.
2. These motile erythrocytes are usually hypochromic, contain mitochondria and neutral red-stainable granules, all of which are attributes of normal but immature red cells.
3. Motile erythrocytes similar to those found in the blood of human patients with anemias are found in the blood of normal rabbits and mice.
4. In the marrow of patients with macrocytic anemias, megaloblasts and megalocytes may be found which give rise to motile erythrocytes by budding.
5. Poikilocytosis, motility, paleness, content of mitochondria and neutral red stainable granules, and origin by budding from a large parent cell do not differentiate the erythrocytes of pernicious anemia from those of other anemic states.