“…(For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) systematically demonstrated to be quasi-fractals by others when studied separately from the capillary component (Gazit et al, 1995;Sandau and Kurz, 1997;Kirchner et al, 1996;Wilting et al, 1996;Vico et al, 1998;Parsons-Wingerter et al, 1998;Bergman and Ullberg, 1998;Herman et al, 2001;Masters, 2004;Cassot et al, 2006;Kassab, 2000;Gan et al, 1993;Jiang et al, 1994;Hahn et al, 2003). Because of the variety of vascular structures considered in these studies (subcutaneous, extraembryonic, pial, retinal, coronary, pulmonary, hepatic, intracortical) and because the homogeneous nature of capillaries has also been demonstrated in various systems (subcutaneous (Gazit et al, 1995;Baish and Jain, 2001), epifoveal (Panico and Sterling, 1995), hepatic (Gaudio et al, 2005)); this conclusion appears to be very general.…”