Silver impregnation of collagenous microfibrils has been applied in electron microscopy in recent years by yon Herrath and Det tmer (3), Dettmer, Neckel, and Ruska (1), Det tmer (2), Schwarz (5), Tomlin (6), and Irving and Tomlin (4). The main purpose of these authors was to determine whether the silverimpregnation picture of the so called reticulin fibers differed from that of the collagenous ...