The authors summarize all that is known at the present time about normal and pathological eliptocytosis. They present 20 observations of normal persons, the results of which showed a smaller excentricity than that described by the European authors: 2000 red cells in 20 normal persons. I 71, II 26, III 3, IV 0, I.E. 1,06, E.E. 3. They reassured the fact of a hypereliptocytosis in pernicious anemia. A case of constitutional hyperexcentricity is detailed in which the result was constant during 5 years. Lastly they describe in a fatal case of reticulo-endothelial leucemia a highly pronounced hyperexcentricity: 300 red cells observed I 14, II 27, III 35, IV 24, I.E. 5,63, E.E. 59. Measuring the excentricity of the red cells shown in the microphotographs and sketches of several papers dealing with monocytic or reticulo-endothelial leucemia, the authors verified in the final result, a very clear hiperexcentricity.