As was demonstrated in the 1st report the granulocytes in the circulating blood of a normal adult rabbit showed the increased permeability for dyes in the range of pH, at which the electrical changes of dyes decreased-alkaline media for basic dyes and acidic media for acidic dyes. In this paper the same experiments performed on the bone marrow cells of normal rabbits have been represented. Observations on myeloblasts, promyelocytes and myelocytes using B.C.B., Nile blue, neutral red and Janus green as basic dyes and eosin, erythrosin as acid dyes revealed that these young cells has an increased permeability for basic dyes and a depressed permeability for acid ones comparing to those of matured granulocytes, e.g. young cells in wet preparation showed an increased stainability for basic dyes at the pH level of 4.8 to 7.0 and a depression of permeability for acidic dyes at the pH level of 2.2 to 5.6. Discussions were made on the difference of permeability between bone marrow cells and matured cells in the relation of maturing of cells accompanied by the elevation of isoelectric point of cytoplasm.