Pauli reports in detail on Pais' lecture in Holland on "isotopic spin and mass quantization" and on his introduction of the "W-space". Pauli writes about Jordan's cosmological equations. Pauli thinks that Einstein's model is simpler and more convincing. He does not see the advantage of the introduction of a changing gravitational constant. The appendix contains ideas about the statistical theory of heat.

Pauli requests reprints of Wergeland's latest work for a letter of recommendation.

Pauli describes his role in preparation of the Bohr Festschrift. Pauli gives his views on biological questions.

Pauli writes of his doubts concerning commutators in Klein's Bohr-Festschrift article.

Pauli advises Klein on improvements to his Bohr-Festschrift article. He reports on receipt of Landan's article. Pauli makes remarks on Soviet contacts with the West.

Pauli makes editorial remarks on Klein's article. He reports on his trip to Holland.

Pauli awaits experiments on beta-decay "neutron" hypothesis. Pauli asks for an answer from Bohr to Pauli's arguments against failure of energy conservation in his letter of 12 Dec.

Reply from Pauli to letters by Klein, especially about five-dimensional formalism.

Pauli makes a comparison of Klein's theory with his relevant lecture given in Paris.

Pauli gives further details about the impending visit to Sweden.