Pauli thinks it's important to explain the lack of strong interaction in leptons. He talks on the necessity of giving explanations on some points of the table summarizing the properties of the elementary particles.

Pauli comments on the publicity given to Heisenberg's work. He does not believe that any model will explain the symmetry diminution occuring at the transition from the isogroup to electromagnetic forces. preprint of his and Heisenberg's work.

Pauli writes about the publicity given to Heisenberg in radio and press. He writes about the prospects and difficulties of his joint work with Heisenberg. He writes about his participation to the solid-state seminar in Kittel.

Pauli has heard that Landau is enthusiastic about Heisenberg's and his own attempt to incorporate the isogroup into the spinor model with indefinite metric. He enumerates several difficulties of the theory which are not yet solved.

Pauli makes further remarks on Gürsey's formulation.

Pauli comments on Heisenberg's relation with the press. He writes about his work with Heisenberg.

Heisenberg replies to Pauli's letter of 10 March. He gives the result of his latest calculations.