ProFessor G. PONTECORVO, F.R.S.

Hi2b

GENETICS DEPARTMENT

THE UNIVERSITY
GLascow, W.2.

Tex : WESTERN 2865

 

17th October 1956.

Dr. J. Lederberg,
Department of Genetics,
University of Wisconsin,
MADISON, Wiscl

Dear Josh, fn gos : Esiln

Here @wmthe official invitationd/to our small
meeting the week preceding the Ciba meeting. You
can stop in Prestwick (Glasgow) on your way in and do
Edinburgh between the two meetings. I have asked Wad
to clinch the matter of your fare round-trip London-
Edinburgh. If he provides it you would have three
round~trip air fares London-Scotland net: this amounts
to a little less than one-half one round-trip transatlantic
fare.

But Westergaard can do the following: one
first-class round-trip air fare London-Copenhagen plus
500 Danish Kroner. I believe that if you take a
round-trip ticket New York-Copenhagen you can do all your
travelling in the British Isles and asfar as Paris
without extra charge. Boris, incidentally, is trying
to arrange something in this connection. If this is
right (Scandinavian Airlines will tell you), the little
extra which Westergaard and myself, and probably Wad and
Boris, can provide would almost amount to another fare.

Please let me know promptly whether you can
manage under these conditions, so that I may try to get
everything settled.

And now as to our meeting on recombination.
Would you care to be the one who introduces the discussion
on bacterial recombination, leaving out transformation,
about which I shall ask Hotchkiss or Harriett Ephrussi?
We should try to keep these introductions to less than one
hour so that we may have another two hours for discussion.

It looks as if Esther's story on Lac (Lewis effect

of /
20

of one mutant with two groups which are complementary)
were exactly as the ad13, ad15, adi7 situation
described by Calef in Aspergillus: i.e. 15 and 17 are
complementary, and 13 gives the Lewis effect with both.
In this case we know that 13 is not a double mutant
(summary in 'Heredity').

Looking forward,

ea