Abstract
Electron microscopic survey of tuberculous lung lesions of mice revealed a novel type of lymphocyte-macrophage association. The finger-like projections with sharp or blunt tips of lymphocytes are formed as if pushing deeply the macrophage membrane to form pockets matching the shape of the projections. Intimate membrane contact occurs between these two cells, particularly at the leading edges. The biological significance of this morphological event remains to be a subject for future study.