Pauli discusses on invariance of the relativistic wave equation.

Pauli talks about the preliminary report on their joint work. Pauli does not believe anymore in many of the statements in this report. He has written to Heisenberg that the assumption of vacuum degeneration does not seem necessary to him. He writes about his talk with Gürsey in Brookhaven. Pauli expresses his optimism about the solution of the general formal questions, which have nothing to do with group theory. He believes that the symmetry violations do not depend on arbitrary terms in the Hamiltonian but on the metric in Hilbert-space.

Pauli says that the spinor model may be wrong, but Källén's considerations do not yet prove this as Pauli undertakes to demonstrate.

Pauli discusses the properties of spin matrices and efforts toward a quantum electrodynamics.

Pauli asks Jordan to send his cosmological works to Prof. Lichnerowicz at Strasbourg. He writes about Jung's interest in parapsychology. He has a negative opinion about a book by an American psychologist, E White, on the "Unobstructed Universe".

Pauli replies to a letter about affine field theory. Pauli explains why the unity of field theory is impossible, because the reduced curvature tensor splits into a symmetrical and antisymmetrical part, which can never be brought together again.

Pauli writes on additional calculations about Jordan's theory of gravitational constant.

Pauli gives some details about the confor-transformations in Jordan's field equations.

Pauli writes on the concept of chance in biology and on the lack of a quantitative definition of biological probabilities. He suspects that the present conception of evolution is still essentially incomplete. The two parameters of selection and mutation are logically independent of each other. It is not the gene that is thesmallest unit of life but the cell as Bohr has emphasized.

Pauli replies to three questions of Jordan: 1) on heat conductivity, 2) on his possible visit to Hamburg, 3) on a problem which Delbrück might be able to answer.