During the last years, many technical realizations of memristors have been conceptually and practically realized. The theory behind the memristor has been extended as well but mostly for memristors and less for electrical circuits with memristors which are often difficult to analyze due to the nonlinearity and the dynamics of the memristor. The theory of single memristor networks is the very aim of this paper. Based on the Multilinear Theory of Nonlinear Networks and on Volterra Series representation, a general description of single memristorcircuits is obtained.