NEW YORK UNIVERSITY—BELLEVUE MEDICAL CENTER

NEW YORK UNIVERSITY COLLEGE OF MEDICINE

550 FIRST AVENUE, NEW YORK 16, N. Y.

DEPARTMENT OF PHARMACOLOGY September 12, 1956 OREGON 9-3200

Dr. Joshua Lederberg

Department of Genetics

The University of Wisconsin
College of Agriculture

Madison 6, Wisgonsin

Dear Joshua:

This letter is the first one I'm trying with the new magnetic
dictating machine we're just buying so I'll probably be more verbose
than ever for the next few days while playing with this toy.

We have no intention of looking into the morphological side of the

DAP story. I'm delighted that you think you might do something with it,
since I've felt that the results of our experiments were so predictable,
on the basis of your work, as to be pretty trivial. Anyhow, I'm
enclosing auxotroph M173-25, which has an absolute requirement for

DAP and a relative requirement for lysine, and am also sending a salt
of DAP WHich we'ver recently obtained from Charlie Gilvarg downstairs.
The salt conta ins Metweer30-and lio per cent DAP, and its other con-
stituent seems to have no effect on bacterial growth. DAP is not,

so far as I know, commercially available, but I'm going to suggest

tc the California Foundation that they try to prepare some.

Unfortunately, we don't have any DAP auxotrophs in Kl2. I doubt that
your lysine auxotrophs would do you much good since they would not
grow well on lysine if they had a reasonably complete block before
DAP.

 
    
   
 
 
 
 
   
   

I also have some more interesting results to report. The trip back

from Woods Hole on the Labor Day weekend was uneventful, and a week later,
after rather prolonged labor, Liz gave birth to a boy whom we have named
Franklin Arthur. Birth weight 7 lb., oz., mother and child doing
beautifully, and father deathly scared t this extremely noisy, active
infant will be a hellian that will leave no peace in the house for many
years to come. On the other hand, I always used to think that new-born
babies were ugly, and it's amazing how beautiful this one is. All kidding
aside, I'm really excited at having a son, and we're hoping Liz will be
strong encugh so that we'll be able to spend a weekend in late October

at our cottage in Woods Hole.

I'm not surprised to learn that you have further evidence that the L forms
are simply protoplasts tough enough to proliferate. I'm sure that your
few simple observations have wiped out the whole messy literature on
protoplasts, and I imagine you'll soon be looking for other problems.
Best regards to Esther, and greetings from Liz and Frankie,

Sincerely,

Bernard D. Davis "G Qsecee