July 1, 1948.
Dr. James Craigie, |

Imperial Cancer Research Pund,
Burtonhale Lane, The Ridgeway,

WG MSN), London, ue 7,
Dear Dr, Craigie,
In your review paper fn Bast. Reve (1946) you refer to your fogotnatiog

work with the gamna plages of the typhoid organiea.If you have published .
| your work sonewhat more extensively, I would be grateful for ‘the referense

or a reprint. The Canadian Public Health Journal ie not readily aocesaible -
| here, and if the material te not covered olseshere, I would be obliged a
for & rerrint of your abstraste there, ‘I would particularly Like to have -
this materiel for use in writing & review of Bacterfal Variation for
Anmal Reviews.

One point in your discussion was not glear to me (p/ 85): nanely,

that "gam" could convert E to Dy. Ie this conversion accompanied by
lysis of susceptible cells ani selection of D, (albeit lysogenic) variante, mo
oF dove every call in the culture remain intast, shi besone transformed -
to, ? This question has obvious genotic interest.

Tours sincerely,

Jouhua Lederberg, re o :
Assistant Professor of Genetics. oe

fe LY30GEMG CONVEX ete ee a