Una lezione particolare di Ettore Majorana

We give, for the first time, the critical complete text of a manuscript by Ettore Majorana, conserved in the same file of the lecture notes for his course on Theoretical Physics at the University of Naples. He probably refers to a seminar delivered in that University. Some passages reveal a physical interpretation of the Quantum Mechanics which anticipates of several years the Feynman approach in terms of path integrals, independently of the underlying mathematical formulation.