Dr.Wolfram Heumann,

Oberassistent am Botanischen Institut
der Technischen Hochschule Braunschweig
Braunschweig

Humboldtstr.1. 5.Dezember 1955.

Herrn
Professor Dr.JoshuaLederberg,
Madison

University of Wisconsin,USA.

Dear Professor Lederberg,

with great interest I watched your treatises about the recombination
of hereditary factors of crossing Escherichia coli K-12 mutants.

As genetics has to be regarded as the most exact of biological sciences
the results of this way of research have an especially great power of
evidence.Therefore the conclusions dramwn by you upon the sexual modus
of Escherichia coli on account of your genetic studies appear to me
well foundet.

In comparison with this,all researches upon the sexual modus of
bacteria,using the morphological or cytological studies,are subject
to a certain insecurity considering the limitations given these methoda
by the physical laws though these methods have the advantage to be
more obvious.

In the last years I profoundly analysed the sexual modus of star-
forming bacteria by using morphological and cytological methods .The
most important results are described in the study enclosed.As to this
I should like to lay stress on the fact that any time the whole sexual

cycle may easely be reproduced on plood-mediums with the selected

strains of bacteria,and that the analogies to the sexual relations of
higher microorganisms are most apparent.I belive that the morphological-
cytological study of the sexual mode of bacteria has reached a stage
which seems to make it necessary and productive to join it with the
genetics.As the installation of the institute where I am occupied,

is not sufficient enough for the work of a genetic exploration of the
subject,and as there is no special assistent-staff,I beg to ask you
if these studies can be carried out in your institute .If you could
make that possible I should regard it advisable to save time for me
to come to your institute at Madison with the strains of bacteria to
take part in the studies under your guidance.I would consider it a
special honour for me to work,may it only be a short time,under your
guidance. .

First of all,I beg to ask you kindly,if you are interested in the
subject,for a short opinion or judgement of my enclosed study that
might help me to make a motion for financial support with our autho-
rities.

Thanking you in anticipation for all your trouble I remain

Yours very sincerely,