Pauli writes that he accepts the invitation to a lecture at the Institute Henri Poincaré and suggests to give the talks in English. The subject of the lectures is "selected chapters of the theory of quantized fields".

Pauli refers to two manuscripts sent to him. He encloses a copy of a letter to Bohm outlining Pauli's criticism of Bohm's "Hidden parameters".

Pauli expresses his delight over Destouches' impending visit in Zürich.

Pauli critizises a paper by Destouches on the physical interpretation of wave mechanics. He also implies a criticism of Louis de Borglie's point of view, given in his paper in: J. Phys. : 8 (1927), pp.225.

Pauli writes of a letter by de Broglie clarifying the point of view published in: J. Phys. : 8 (1927), pp.225. He also criticizes a recent publication by de Broglie dealing with the Schrödinger equation.

Pauli looks forward in meeting Destouches on March 3. He thinks that he could reach an agreement with him on the points that are under discussion.

Pauli thanks Delbrück for the copy of his lecture. He hopes that biology will soon have a development analogous to that of physics from 1900 - 1905. He is interested in processes in living organisms which cannot be explained by quantum mechanics. There may exist in living organisms, besides statistical laws, an additional interdependence which might explain biological evolution.

Pauli replies to some issues raised in de Shalit's letter of 6 March, including: strangeness; the role of particles with rest mass zero for the decrease in symmetry (group-invariance); the ^-conjugation formalism; and a "philosophical" problem.

Pauli thanks de Broglie for sending him his paper "La physique quantique restera-t-elle indéterministe ?" Pauli makes some critical comments on it.

Pauli thanks de Broglie's for his contribution to the issue of the "Dialectica" dedicated to the problems of complementarity and he makes some comments on it.