Following the study on the characteristic traits of the synovial fluid and the blood in rheumatoid arthritis by the fluorescence antibody techniques as reported in a previous paper, histochemical and morphological observations were carried out by various staining methods using the synovial fluid and blood from the patients with rheumatoid arthritis in order to further clarify characteristic traits of leucocytes. The results are briefly summarised as follows. 1) It seems that the appearance of "RA cell" that correspond to what is reported by Hollander and his co-workers is not necessarily a phenomenon specific to rheumatoid arthritis. 2) There is a correlation between the number of "RA cell" and the number of nucleated cells (leucocytes). 3) Ketoenol granules have been found to reveal a similar distribution pattern as that of inclusion bodies (as observed not staining the cells). 4) It is difficult to identify the granules of inclusion body of Hollander at a rheumatoid factor, but these granules can rather be identified as ketoenol granules by the carbolfuchsiniodide method, and they seem to represent one of degenerative granules. 5) It was not possible to identify any granules that corresponded to those granules positive to the fluorescence-antibody reaction as reported in a previous paper.