“…Although the application of Strahler's [ 130 – 132 ] and Horsfield's ordering methods [ 68 , 69 , 138 , 139 ] could have reduced the variability between the measurements which were made on the branches in this study, for the reasons given below, the morphogenetic ordering method was preferred. We subscribed to the consideration of Weibel [ 95 ] and Hsia et al [ 129 ] that for the human lung, the morphogenetic ordering method provides more instructive data for understanding physiological processes such as flow dynamics [ 95 , 138 , 140 , 141 ] and particle deposition [ 142 , 143 ], while Strahler's ordering method yields more meaningful data for the pathologists [ 129 , 138 ]. Furthermore, Horsfield [ 138 ] cautioned that a great deal of information is lost in the simplification inherent in Strahler's ordering method, especially with regard to the connectivity of the branches.…”