~ 7 mom

August 25, 1954

Dr. Ellis Engleaberg

Hooper Foundation

U. Califorhia Medical Center
San Francisco, Calif.

Dear Ellis:

I have received a letter from a Dr. Re Devignat, who works on Pabtaurella
pestis at Elisabethville, Belgian Congo. He writes that he has been studying
three distinct notural varieties, and,more to the point, that he has some
experiments with them that suggest the occurrence of genetic recombination
among, the strains. Hie characters are virulence, on the one hend, and
biochenical traits such as glycerol fermentation, nitrate reduction, etc.,;
on the other. He says very little about controls on the stability of the
markers, but by and large he seeme to be appreciative of the pitfails.

At any rate, Devignat "pourrait mettre a (ma) disposition une serie de
souches des trois varietes sous leur forme tres virulente, sous forme
attenues, et vaceinante, sous forme attenuee et a peine vacchnante, de ree
que les souches dont les colonies ont des morphologies dif rentos..e. ¥
joindre les hybrides dont question ci-dessus et donner des detaile concernant
les sonlitions de culture qui m'ont parus les plus favorables « L'avparition
des hybrides ou o leur detection." He acknowledges that his own lab. facilitios
are quite mediocre, and avpears understabdably cuite antiouy to have his
observations confirmed and extended elsewhere.

It de cuite obvious that you would be far more comptent than I (or anyone
elee I can think of) to render such a service, and I hoped that your interest
woul!) be comparable. May I reply to Devignat that I have discussed this with
you and that you have assented to exanine his material:

Yours sincerely,

Jochua Lederberg
Professor of Genetics

ele Ye will be at Woods Hele to about
Septerher 3, then bac! to Madison.