March 20, 1952

Dear Tom:

I'm sorry to have taken so long withbyour ms., but I had too many
things of the same kind waiting for me to be able to get to it sooner.
I have not given it so detailed a raking-over, because I thought that
you could do the same yourself, Frankly, it reads as if it were rather
heavily padded. I would think that the most appropriate form for such
a contribution would be to subjoin the general results of the genetic
analysis and put the two together as a note in Arshives of Biochem.
The imtatlon la certainly interesting from a chemical-genetic standpoint,
but until the details of malate and succinate utilisation are unravelled
it is sore an advertisement of something interesting to cone, rather
than a fuliy rounded accomplishment. I have a few specific notes, marked
in red on the margins:

a. A little mre needs to be said sbout the origin of your s- K-12, I
don't think that our stock is s-, but am onclosing it for your inspection
and comparison. If this is right, you should refer to s- as a matant substrain
ef quastionable ordgin, and the emphasis of identification falls to the s-!
In view of our routine use of EMS medium, this question of the character of
our standard K-22 stocks te bound to recur if not made clear at the outset.

2. "claasteal. coliform” {s what?! You don't really have to he 80 cagey
about contamination (in print). The evidence can be there without being
overemphasized. Table IT is superfluous, conclusions are siBficient.

3. vefer to T-S atant only if s- X12 48 deseribed as 2 mitant.

4. Sea 8

5. Was limiting factor simply scépe of these experiments? What are details
of original isolation of $+? Could spt be simply « residual orighnal K-12?

6. See enclosed reprint. (By the way, let me know which papers of mine you
havs, so I can bring sy distribution file up to date. Thanks. )

7. I dén't see the point of dragging in the kinetics figures in this
paper. Why not cite Nelson 1951, end mention agreement.

8. That's the rub.

9. The genetics should come here too.

_# Sincerely,

Joshua Lederberg