Forma, Vol. 31 (Special Issue), pp. S3–S15, 2016


Branching Structures in Nature and Human Societies

Ryuji Takaki

Tokyo University of Agriculture and Technology (emeritus professor), 2-23-12 Yuigahama, Kamakura, Kanagawa 248-0014, Japan
E-mail address:

(Received July 19, 2015; Accepted March 25, 2016)

Abstract. Several examples of branching structures in the nature, social structures and the human body are introduced, and results of their analyses are given. It is shown that the Horton’s law, which is confirmed for river branching structures, is satisfied also in variety of branching structures in the nature and human societies. It is suggested that these structures are constructed owing to mechanisms similar to that for river structure. As for the branching structures in human body some trials are introduced to construct them numerically by the use of mathematical models. The object of this review article is to show that the analyses of branching forms are interesting topics as the science of forms.

Keywords: Branching Structure, Tree, Network, River, Horton’s Law, Natural Structures, Social Structures

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