Heisenberg replies to three letters from Pauli who is in New Yok.

Pauli replies to Heisenberg's letter of 10 February to tell him that in Berkeley he has the opportunity to discuss their work with many people. He has more questions about the mirror-world (mirror nucleons and mirror difficulties of the spinor model and some problems of mathematical formalism.

Pauli returns briefly to the mirror problem.

Pauli gives more suggestions for the preparation of the publication. The connection of vacuum degeneration and strange particles must be emphasized. He has other suggestions for a clearer representation of their results.

Heisenberg replies to the objections of Pauli in his last two letters, concerning the second draft of their pre print.

Heisenberg writes of the distribution of their common pre print. He suggests the next steps as regards the paper and its disposition.

Pauli replies to a letter of the 24 February 1958. He writes about his work with Heisenberg in general and criticizes emphatically Heisenberg's radio publicity. He makes some remarks on biology and neo-Darwinism.

Pauli replies to Heisenberg's letter of 25 and 27 January. He writes about particles with rest mass zero and leptons with rest mass different from zero which have no strong interaction. He talks about the radio publicity given to heisenberg.