September 3x, 1950.

Ams rican type Culture Collection,
2029 M Street,

Washington 6, D. C.

Gentlemen:

In the fourth edition (1938) of your catalog, you list Flavobacteriua
lutzae (Brown), cultures 4417 and 4418, These cultures sre not listed in
the fifth edition. If viable cultures of these strains are available,
please ship them to m.

I should also like to receive Escherighia coli 4157 [Please do not

. substitute].

A purchase order will follow your information as to the availability

of the above cultures.

I would appreciate being placed on your mailing list for your catalog

and similar notices.

Yours sincerely,

Joshua Lederberg,
Asscelate Professor of Genetica