Fierz sends various remarks on a letter by Pauli.

Fierz sends some considerations about elementary processes and their connections.

Fierz comments on a paper by Stückelberg on the radiation theory of photons and similar considerations made earlier by Fierz.

Fierz writes of his correspondence with Yang about the latter's paper on a gas of rigid spheres. He also writes of his talk with Villars on the latter's work on collective coordinates.

Fierz continues his last letter of the 6 February 1957 about the two component theory of the neutrino. In the absence of forces this theory exhibits mirror invariance.

Fierz makes comments on a paper by Salam which was sent to Fierz by Pauli.

Fierz writes on the theoretical interpretation of certain Beta+ - disintegration experiments.

Fierz writes on interactions leading to a violation of parity.

Fierz writes on calculations concerning fields with spin.

Fierz makes critical remarks on a perturbation calculation by Pauli with special reference to the elimination of non-physical states.