Lopes reports on his investigation of the angular distribution of high energy neutrons by protons in the pseudoscalar theory with a strong coupling.

Following Pauli's letter of 14 March, Lopes compares his paper "On the particle picture of quantized Bose Fields I" with Dirac's paper.

Polvani forwards the written response by M Born to Pauli's criticism at Firenze Conference in 1949 (attached).

Potier sends some reprints on mathematics of quantum field theory.

Schaumann sends a manuscript of attempt to synthesize macro- and microcosm. He talks about pair production.

Vrkljan sends a reprint on the problem of neutron and proton.