awn

July 8 1951.

Dr. Werner Maas,
Tho. Research Labye,
New York, N.Y.

Dear Werner:

If you oan conveniently arrange your wiesit for the firet part of
August, about one month from now,we will be delighted to have you.

If the visit ie to be profescionally fruitful, I suggest we plan
carefully the things we should go ever. I imagine that are going
to be most interested in handling heterozygotes of /*%, but this
should be plamed carefully tgforehand. the firet datum needed is the
linkage position of the Pnt loous- 44 would be specially useful to
have 1t located in reference to such markers as Mal, Lao), V) ote.

If thie has been done, it will then be possible to plan bie dotaais

of the cross. If I may look thet far ahead, I would recamend that

we initiate the necessary crose prior to your arrival, so that the

cross plates will be avhilable for your examination and picking, together
with the necessaty media, as soon as you get here.

Did you or Bernie say something to the effect that the overall
activity of the pnt-t mrtent was #0 much lower than that of pnt/
that it might be difficult to detect both types of enzymatic behavior
in heterozygous cells, even if the alleles acted autonomously. If this
is so, do you still want to pressed with this problem?

May I suggest then that we proceed at once to review 1) the stooks
of K~l2 that carry pnt-t, and are otherwise suitable for crossing, and
2) the linkage data that you may have accumlated on the locus.

Of course, I may be way off on what you plan to do here, so please
let me know about it.

Best regards,

Sincerely,

Joshua Lederberg