The effect of the LE-cell factor lies in nuclear blockade; the normal degenerative nuclear swelling and lysis is inhibited. 2. The time of the nuclear blockade and thus the appearance of the LE-bodies depend on the activity of the LE-serum. 3. High-titred sera lead to an early nuclear blockade. Small, rigid, dark, clump-like LE-bodies appear rapidly and are fully phagocytosed. 4. Our experiments have shown that with decreasing activity of the LE-sera the nuclear blockade appears later and more slowly. Such LE-bodies are relatively large and homogenous and have lost some rigidity. They are correspondingly late and only partly phagocytosed. So-called granulocytic and monocytic Sjögren-cells appear. 5. We found that quantitative differences of the causal factors lead on the one hand to LE-cell formation, on the other to the partial phagocytosis phenomenon. Therefore, we prefer not to label the Sjögren-cells as pseudo-LE-cells. 6. It has again been shown that the standardized supravital preparation is not only a simple method for demonstrating LE-cells, but is also superior to other methods used because of its greater specifity and sensitivity. Besides the judgement of cell vitality, many hours after making the preparation phagocytosis can be observed.