“…However, some inves tigators were o f the opinion, that CSF lympho cytes originate partially from the leptomeninges (Fischer, 1906;Szecsi, 1911;Sayk, 1960;Bisclioff, 1964Bisclioff, , 1971 In the last 15 years immunology has devel oped rapidly, in spite o f which only sporadic and partial attempts have been made to bring these new findings into CSF cytology (Guseo, 1972(Guseo, , 1974Oehmichen, 1973;Allen et al, 1975). One must consider that about 15 years ago the role o f lymphocytes was still question able -here was a relatively small cell that morphologically was dull and unattractive, while in contrast, the cells that apparently were involved in an active immunological process were large, full o f organelles, and actively syn thesizing proteins and/or antibodies.…”