Heisenberg makes a comment on the case of 2N+$\Theta$.

Heisenberg gives more calculations about zero-vectors and dipole ghosts.

Heisenberg gives more calculations about dipole ghosts and the unitary character of the S-matrix.

Heisenberg talks about progress he made in his work on the Tamm-Dancoff method and the Lee model.

Heisenberg replies to Pauli's questions mainly about dipole ghosts.

Heisenberg discusses the connection of isospin with the duplication of the vacuum.

Heisenberg explains his objection to Pauli's suggestion as regards the communication relations. He suggests the publication of a preprint.

Heisenberg replies to Pauli's last letter about vacuum degeneration and about unitarity of the transformations.

Heisenberg writes of his progress as regards the eigenvalue problem. He writes about the contents of a preprint.

Heisenberg talks about the univalent definition of the Lagrangian by the groups and about the mirror problem.