March 10, 1955

Professor John von Neumann
Institute for Advanced Study
Princeton, N.J.

Dear Professor von Neumann:

T have h if several intimations from my reading and discussions with
friends (c.g: Professor Sol Spiegelman) that you have contributed to the
problem of the minimm information required for"self-reproduction! or to
related problems pertinent to genetic theory.

Are you considerations recorded in print? If so, I would be indebted
to you for the literature citations, or, if available, to any reprints.
I have access to several sources of mathematical advica, if the techniques
are beyond my own means.

In connection with my own more mundane research on genetios of bacteria
and viruses, I have had occasion to feel rather uncomfortable at the adequacy
of the genetical concept of "self-reproduction", or rather at the operations
by which this is inferred for any sub-cellular particle, and I am therefore
hoping to reexamine the problem afresh. Since moat intracellular particles
will not reproduce at all outside the context of a given kind of cell, the
criteria for the capacity of "self-reproduction" of individual genes, etc.,
may be gepssly def ieient. ‘

Yours sincerely,

Joshua Lederberg
Professor of Genetics