(Laboratory for Microbial Genetics)

October 11, 1949.

Dr. Kaare Lilleengen,
Bacteriological Hygiene Department,
Royal Veterinary College,
Stockholm, Sweden.

Dear Dr. Kaare Lilleengen:

It has been some months now since I had expected a further word from
you concerning the possibility that we might have transfers of your sys-
tematised phages and cultures of S. typhimuriua, for our genetic investi-
gations. I fear that our correspondence may hare been interrupted by some
mishap in the trans-Atlantic mails, or else that in the course of your
movement back from London, you might very understandably have overlooked
my previous request.

I hope, therefore, that you will not take it as a sign of impatience
if I write you haww renewing my earlier request. It would be of very great
help to us to have am organized set of cultures such as you reported in
your monograph, and we should be very grateful for your cooperation.

Thanks, algo, for having sent the reprint of your "Typing of Salmonella
typhi mrium by means of bacteriophage.
Yours sincerely,

Joshua Lederberg,
Assistant Professor of Genetics