October 20, 1952
Dear Bruce:

Your letter of the 14th just received and duly deciphered. You must
not have received my previous letter when you wrote thie-- I am not sur-
prised: through seme lapsus menti, I addressed &t to the Londen PG Med
Schdol! Af you haven't got 1t by now, you should probably sem send over

  
  

I last wrote, I wae dust about to set up the progeny tests

‘for Ahé "linked traneductions® to sW-543. For a while, I thought that

“only 4 phases were appearing, but this misapprehension was due to a dis-
erepancy between the effectiveness of a eerun in immobilizing in agar, and
in agglutination, I still don’t knew the reason for this, but applaut the
prospect of a esmplete serplogical analysis of the transinduced phases.

I have also the observation, frem SW-545 x FA (abony) of & phases which
gave swarms in b agar. These reacted still, albeit weakly, only with b.
These “attenuated b's" are still perfectly motile. I'll send you some of
these, with notes. Transductions cf other phases to SW-543, accompanied
by b's in each case, have been verified. Theyt include @/ gm (enteritidis),
gp (dublin) and r (heidelberg). I expect to do the progeny tests on the
latter to help sew up this part of the story. Bt b's are definitely coming
out of SW-543 + Fa( SW-623). I have seme rune new on the second generation
i's frem thie same combination, and think we can stop here. I see aux no
way out of linked transduction, perhaps of components of a gene characterized
by pseudo-alleles. It looks much the same ae “autogenic" transformation in
pneumocecous. There is no sign of linkage with another marker put into
SW-543 (SW-666 = 545 Gal-, used in most of these). Norten is willing to
admit that the spontaneous 1 was a fluke; the experiment involved heated
PA ae a control, and it presumbbpy was not completely inactivated.

Souvlé like you have some very nice new material, but let's call a halt
and write up the summer's work before you've chased down too many other
quarries. The Lag¢ sharacter sounde promising, if you can get FA out of it.

Bpicey has beeh here about a week, and trying to make sense out of his
S. thompson's and their phages. So far, they haven't been built up to £ uf
ficient titre for any interestimg purposes. My immediate ambitions

Instead ail Me wot dilmidsathcoRGPk OP going
: Bole nea : seer et Popeyiearson 19). ttt

‘a phage carr

e

a far by the use of heat
a have missed any B phages 90 sat y he
teary ee Lysates. If 3. bovis morbificans is really so generany
: fr conclusls
the A phages, we may have to revise our ©
see tt ae receptor. Tt has not yet bern tested for absorption of Fa.
“& £

rnglish skewers— not for
asks please not to bother about Engl
thie winter ? anyhow. I append a pedigree diagram on what has beea

done so far on SW-543 genetics