INDIANA UNIVERSITY
BLOOMINGTON, INDIANA

DEPARTMENT OF BACTERIOLOGY

September 7, 1949

Dr, Jd, Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Joshua:

Thank you very much for sending the manuscript, one copy of which I
have given to Bernie Davis asking for his comments, as I told you I
would do. I have a few suggestions that I would like to include, if
you don't mind,

In the first place, I think at Fage 5 the reference to the paper by
Davis in the J.A.C.S. should be added,

At Page 7 I would add after the first paragraph the follewing sentences:
"The concentration of penicillin suggested (300 units per ml) is required
because of the low sensitivity of organisms such as Salmonella or
Lscherichia. Lower concentrations may be sufficient for other organisms".

a 9
At Page 10, Line 4, I would indicate the concentration of Tween 80/54:

At Page 17, I think you should expand the paragraph on genetic recombina-
tion to about one page, including statement of the reasoms why no specific
techniques are given. In the present form, in spite of a few attempted
changes on my part, it will be almost completely ununderstandable to the
unacquainted reader,who would not understand the reletion of nutritional
mutents to recombination unless the basic experiment is descrited in a
little preater detail,

I hope this will be the last time I shall bother you. The next time you
will receive, I hope, a check, which is supposed to cover the typing and
mailing expenses,

With best regards,

nw
vb S. B, Luria
P.S. Please let me know if your title, to be included in the Volume, is

correct as follows; Assistant Professor of Genetics, University of
Wisconsin, Madison, ifisconsin.e