February 5, 1956

Dr. P. D, Skaar
Bio Lab
Crld Spring Hatber, L.I., N.Y.

Dear Dave:

It. wae theughtful ef yeu te send the ms., and I was glad to go over
it. The simplest wey te add my emmments was te mark the carhen copy th
ink, I spotted e few cases cf language that en enterprising student
eculd succeed in misinterpreting, and an equally small number of minor
verbOsities, all indicated, Frankly, I don't care for the "bipartite"
phreseclogy, as it reminds te too seen ef Tracy's shepwern ideas on
kappe, & leng time age, and it might evcke simflar commetations in
others, Why net twe-jecus, tr binary, or duel, or interectdions...?

As to the credit line, the authcrship is, ef course,all yours. However,
I think it would be apprepriete te indicate where tre work wes dene in the
follewing ways: In the address to gdd from "Department of Genetics, University
of WiscOngin, Madison, Wiscensin® end footnote this to read
i. Paper Nuxber frer. the Department Of Genetics. The werk at Medison
(1951-1953) wes supported hy grants fren the Nations] Cencer Tastitate,
(C-2157), Publiz Health Servics, sad fren the Research Ceanittes, Graduate
Scheel], Univebsity ef Wisccnain with funde allotted by the Wisconsin
Alumni Research Foundation,

Als®, can yOu arrange for us tO have about 100 of the reprints when they
cOme back? We will gladly arrange t© pay pro-rata for them.

If yOu can spare a cOpy Of the final ms., I'd appreciate seeing it.

Esther's reply to your inquiry about Mal-Lpo must have crCssed your
letter in the mails, We're a little behind our work, what with being trans-
planted in Bact. Bldg— we should be moving back t© a rem®delied lab in
Geneties in a couple Of weeks. I'm a little afraid you'll be running dowm
the garden path with the Mal mutants, since s© many loci are invlved, but
as Esther said you're welcome to try your hand at it as far as she's concerned,
Wouldn't 5°—~sT be a cleaner system? Ur the Vy,cTr™ (which stands On about
the same ground as Mal_Lpo?

After a lot of fuse and feathers, it finally is clear tO us that Hfr—l
(Cavalli) and - 2{Hayes) are quite different in segregation behavior, What
focled us s© long, or rather got in the way, was that Cur Old stOcks (incll,
@.g., your K-18) are mostly F+ reversions (sic), but we have that cleaned up
now, Alan Richter since picked up two more Hfr's, and I'm well ©n in a hunt
for more, from UV'd Wé, using a replica teehnieuw. Quite a number Of divers
Hfrs have turned up, with all kinds °f segregation ratios-- nOw cOnes the
werk Of analysing them, Have yOu gOt a clean Hfr-2? (1.e., like the one
used by Jac&b?) I can now provide this either as Bl-, pretetroph, or MS”
if you're ay all interested. YOu als© ssid sOmething abOut a well-marked

F- strain that was V 5, Will a v\* ae? If s©, I can send a TLTh”-Lac-Mal-
Are-Xyl-GaL,- S5 or 8” as you prefer, Are yOu and/or Alan ging °n with

the tracer studies? I'm especially serry yOu didn&t get on to F+ x Fe crogses,

Which reminds me, I got a nOte from JacOb this week,, they are evidently
On much the same treil of the various Hfrs, though we dt't azreecen every detail,
naturally. Now he thinks that all erSssing (of F+) is due to ifr miteants, which
seems a little extreme t© me, and in feirly direct contradic:iom te a couple of
items of fact we're stili fogkring on. He has e fluctuation test (fertility of
a series Cf F+ cultures), but if there ever were a case for Kinshelwecds (environ
mentel)cbjection this 1s it, since we knOw what aeratiCn des b¢ cOmpatibijity
phenstype/ (I had abut xhe same dispersicn in a 1946 experinont, but would
put that down te envirOnmentak variability too). I suppose me ctld test the
hevitability cf the fluctuations, but it is a tricky situation, since alnpst
certainly ge of the variable fertility ef F+ culturvs uill be aue to Hfr
mutants,

_ I am on hichter's tail te finish up those F experiments, s® we can due justice
to your literary ambitions in that_direct{om, Nething at all has come curt

ef mere chemstatic experiments: there is 4 marxer-selection experiment in the
werks te see how well F+ and f= inecula ccmpete with oe anctheb, and that

should end it. We've been busy as badgers, but I'ii try wt keep in mind the
backleg sf Skaarian cerrespendence, Den't let tat deter you from keeping in
teuch with us. . . .

The iapressions fleat cut here that you're much vetter settled now at OSH,
even te the print of your deferring seme job ~ppertunities. I hope this is brth
accurate and emegental fer yous if not, let me xn-w xiii and T'll discreetiy
settch the idea,

Sincerely,