iSTITUT SO WILA ESL

12,.xi.52

Dear Joshua,

Your two letters have been received. Concerning the
papers you are interested in,we have got here all the journals and
jt would be quite easy for me to let you have photocopies of them.
As to the addresses of tue people conceined,they are rather out of
date now (except Zironi's address,which is shie-pi-:Istituto di
Microbiologia,via Darwin 22,Milan ; the Institute of Microbiology
of the University is in the same building,and I do some work for it,
though my main job is at thé Istituto SieroterapicojZironi is Pro-
fessor of “icrobviology in this university,and was formerly the fdirec-
tor of the Sieroterapico).Ciantini died five or six years ago.I do
not know Dianzani; 1 hhought his address were Siena,but if he has
moved to Genova T should like to have his new address.His experimen-
ts were very poorly controlled. I have had a look at the other papers.
you mention ; the one by ‘uromtsev is merely a summary of previous |
work. Muromtsev must be a Russian @cientist,although his exact address
is not given,and he fefers to papers of hussian authors but does
not give quotations for them, The other papers contain some experi-
mental data on paraagglutination,with diverse résults.

IT have no important progress to report. Fr x Hfr gives all
F-;whether half of these,as expected,are transducible to F+e,shall
be tested in the futurem. I have no experiments who can say whether
Fe contains an F like agent. Concerning the 1:1 segregation of F+:F-
in crosses wiktk F+ x F’,which seems to me the most peculéar feature
of this experiment, I should be looking for other markers linked
with F in this cross,if any can be found. From the last paper by
Fredericq on ann, Inst.Pasteur,@hich you may not yet have seen,it
seems that colicine E-resistance may be independent from other mar-
kers and segregates almost 1:1. UnSortunately,I find it rather dif-
ficult to secure good resistants to colicines,especially to colicine
E. t

On the question of filterability of F, IT may have to with-
draw my previous tentative conclusiéns. A Mixturesof F+ and F- in
various proportions show that af gr some time,all the culture is F+
even with low initial proportions; there are however,some curious
oscillations in the first stages which I cannot explain for the mo-
ment.

T am anxious to hegg about the kinetic experiments. Concer-
ning Hfr I shall certainly respect my earlier agreement with you.
Thank you very mich for your invitation to the States.I hope to be
able to make use of it.It could not be earlier than 1954, because
 

  

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next year I shall be rather busy with congresses, Unfortunately, my
present pesition will not allow me to spend more than a few monthsyx
away; but Ik would certainly like to come even for a few months.
I shall make enquiries about the possibility of getting a Pulbright
for the journey.

Concerning your coming for the Congress : there will be no
suhstantial financial support for any participant,from the side
of the congress.but there will certainly be some contribution to
living expenses for peopge invited to give lectures. The paper asked
from you wae planned to be in a general session, pn genetic mechanism
s,with other papers by Pontecorvo and Luria,if Mm can come, I hope
you will be able to manage,but you will have unfortunately to look
for journey expenses locally. If you think you may be able to secu-
re them as a representative of some Academy, University, étc.ylet me
know and we shali have a letter of invitation sent to this Univerd
sity etc.Of course we cannot ask that a specific person be sent by
théex University,but the method has worked in a number of otger
occasions.

Please give my best regards to Clive (Spicer)
Yours © 4

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