November 25, 1947.

Dr, Charles A. Stuart,
Dent. Biology,
Brown University,
Providence, R.I.
Dear Dr. Stuzzt,

I am writing to you at the suggestion of Dr. L.W¥. Parr. I
had ingquirec of him concerning certain coliform strains to which

he referred in hid review "Ccliform Bacteria", which epreared some

years ago in Pact. Rev. He suggested that you might have some in-
formation concerning then.

The strains in which I am interested are coliforms which are
tempersture sensitive in re lactose fermentation, i.e., ferment
lactose at room temperature but not at 379. Do you have any such
cultures, or knowledge of them? My interest stems from their pos-
sible usefulness in an analysis of the genetic control of carbo-
hydrate enzymes which I am conducting here.

, Yours sincerely,
| foi

Joshua Lederberg |
Ass't Professor of Genetics.