The surface area per unit volume (Sv), mean thickness (T), and mean length per unit volume (Lv) of the fibrous septa were measured in 15 liver specimens with micronodular cirrhosis, and the allometric equations of Lv on T and of Lv on Sv were calculated. The results supported the view that increases in extension of the surface of the septa were mainly related to increases in their lengths, while thickening of the septa called for relatively short septa of low Lv. As a result, two growth patterns could be recognized in the fibrous septa of cirrhosis. The first one was characterized by collagen deposition around the septa, leading to their thickening; the second one was characterized by elongation of the septa, leading to slender septal branches.