_Jdamuary 2, 1956

Dr. Americo Grosamann
Servico National de Pesquisas Agronomicas
Caixa’Postal 1620, Rio de Janeiro

Dear Dr. Groszmann:
Xixmen There have been few studied bearing on the genetics of nitro-

gen fixing bacteria. However, you might find 1t profitable to consult
the following workers, who have made some studies in that direction:
Prof. A. Kisenstark, Dept. Bacteriology, Kansas State College, Manhattan, Kans.
Prof, w#. R. Zelle, Laby. Bacteriology, Cornell University, Ithaca, N.Y.
Pref. O. Wyss, Dept. Bacteriology, Univ. of Texas, Austin, Taxas.

I wish you all success in your experiments, and hope you will inform

mB of them through your publications. Under separate cover, I am sanding

some reprints that may be helpful to you. The enclosed bibliography may
also be useful.

Yours sincerely,

Joshua Lederberg
Professor of Gene tics