We used the plasmodium of Physarum polycephalum to investigate a communicative property of a cell. We allowed the plasmodium to form a tubular network that connected three food sources, which were arranged to be located at the vertices of an equilateral triangle. The global condition of the plasmodium is changed by the connection of two networks in such a way that the local solution of each network was not affected. We used several criteria to evaluate the character of the network. The change in the global condition appeared to cause significant difference in the network properties, and two connected networks showed homologous network formation. These data imply the presence of intracellular communication and anticipatory aspect in their communication.