Histologic studies of sympathetic ganglia from forty patients with different diseases and of forty normal ganglia were made in order to study the so-called "argentic balls" formations. Impregnations were made by the methods of Cajal, Arteta, Castro, Gros, Bielschowsky and Agdhur. It was demonstrated that "argentic balls" are more frequent in peripheric circulatory diseases; by Gomori and Goldner tricomes method's a pigment was also found; these pigments were related to argentic balls formations, according to experimental works of Russian authors. The presence of argentic balls in normal as well as in pathological cases is tied to hyperfunction of the sympathetic system. It was observed that neurons in close contact with argentic balls, always show alterations which range from the slight (tumefaction of cellular soma, retification of prolongations, strong impregnation of neurofibrils) to the serious (hyperplasia and hypertrophy of dendrites, re-tractible degeneration, pigmentary degeneration). Many times the terminal part of pre-ganglionary fibers and the fibers themselves present hypertrophy, sinuosity and great affinity for impregnation; argentic balls were observed at the ends of both the dendrites and the pre-ganglionary fibers. Rosary-like argentic balls formations were seen and considered as having the same, significance as the so-called claviform alterations. The author concludes that argentic balls are pathological productions.