Letter from Barbara McClintock to Charles R. Burnham
Part of a series of correspondence with Burnham on McClintock's research on csh-wx that would result in an article in
the "Proceedings of the National Academy of Sciences" later in 1931. McClintock sent a copy of the manuscript and
inquired whether Burnham wanted to "go in with" her on the article. A note is also made of McClintock's simultaneous
article with Harriet Creighton. Some data discussed.
Item is handwritten. Item is a photocopy.
Number of Image Pages:
5 (365,458 Bytes)
1931-06-11 (June 11, 1931)
Burnham, Charles R.
Original Repository: University of Minnesota, University Archives. Charles Burnham Papers
Reproduced with permission of the University of Minnesota, University Archives. Charles Burnham Papers
Medical Subject Headings (MeSH):
From Ithaca to Berlin and Back Again, 1931-1935
The Order of the Genes C, Sh, and Wx in Zea Mays with Reference to a Cytologically Known Point in the Chromosome (1931)
A Correlation of Cytological and Genetical Crossing-Over in Zea Mays (1931)
Letter from Barbara McClintock to Charles R. Burnham (March 1, 1931)
Letter from Barbara McClintock to Charles R. Burnham (April 11, 1931)
Letter from Barbara McClintock to Charles R. Burnham (May 12, 1931)
Letter from Barbara McClintock to Charles R. Burnham (June 26, 1931)
Box Number: 3
Folder Number: 4
June 11, 1931
Dear Charlie --
I am enclosing the manuscript for the paper. I have written it asd I think it ought to go. Sharp, Rhoades and Stadler have
worked over it. I made it as short as possible as there could be so much detail which would swamp the meaning for what we
want. The paper which goes with it is Harriet's "A Correlation of Cytological and Genetic Crossingover". I am
growing more material to make the evidence wider in scope but I believe that this is not necessary for this paper.
The part marked in red across the page is the part which you are to do as you like with. I don't know whether you want
to put in a table, make a statement or what. The figures I obtained from a leter [sic] you wrote in December. Maybe there
are more data now. I think you will see what ought to be put in here to give the meaning intended. If you do not like it or
anything else let me know. If you do not want to join with me I should feel bad for your data has been a key for me to work
with. You may not want to take the responsibility since
[END PAGE ONE]
[BEGIN PAGE TWO]
you were not in close touch with this latter work when it was done. I hope you won't feel that way though but be frank
about it and say what you please. Don't injure yourself to please me.
I am anxious to get Harriet's data in press as I have been advised to push it. Since this paper goes first in the same
issue of the Proceedings of the National Academy of Science I am anxious to get it off as soon as possible. I don't know
how busy you are now and whether you can spare a few hours during the next few days to do it. I hope so. Let me know by a
short note what the situation is so that I will know what to expect.
Concerning number 7. Emerson asked me to be certain to cross number 7 with chocolate pericarp. He grew the chocolate pericarp
and I supplied the 2n plus 1 plants. Rhoades remarked that he was going to take care of the crosses, etc. He had talked it
over with Emerson before I saw Emerson. He probably thought he was doing the easiest thing for all of us. I am sorry if you
felt a bit upset about it. I am sure he is doing it as "something to get out of the way" rather than as a special
problem. Therefore you ought to go ahead with what you have on number 7 and chocolate. You will be thru before he gets his
data. I am sure there will be no hard feelings anywhere.
I am growing the material for you on the 6th smallest -- number 5. The ratios 7 to 4 obtained this summer will
[END PAGE TWO]
[BEGIN PAGE THREE]
complete it. So far I have: [diagram] which is ok for a trisome (x) ratio. I shall get v2 corn in soon in the same material.
It looks suspicious enough, though. I shall be very much surprised if anything goes wrong.
I have not grown Beadle's material for sw until I find out about number 8. There is no use of fooling with it when I might
be needlessly repeating. If you get f-br out let me know. I am running some crosses for it and will get it next spring, or
better, summer as follows: 2n plus 1 b-lg plus x-n1. 2n plus 1 F1 will give low steriles in progeny. Low steriles will throw
b-lg 2n plus 1 and f-br 2n plus 1 probably.
Have been here in Columbia 10 days. It was rather hard getting started as there was almost no equipment. Am in
[END PAGE THREE]
[BEGIN PAGE FOUR]
order now and have started work. According to my notes I shall be in Pasadena in October. It all depends on how my work goes
here when I shall get thru.
I believe the knob may be difficult to work in in all cases. There seems to be [diagram] type of synapsis in some cases. Looks
as tho there was no counterpart to the knob (in length if not in quality). Therefore, opening out is not expected. I have
evidence that crossing over occurs before MI and between early pro and ax -- probably according to Sox. The opening out to
form () bis at dk is an expression of the force which breaks chiasmas. My evidence on crossing over is: [diagram] The knob
came in on n chromosome when early prophase observed I find [diagram] In late prophase I find figures which are clearly crossovers
[diagram] in these cases the chromatids were clear as were the spindle fiber regions. I don't believe we shall see an
opening out like this in o-normals where are heterozygous: [diagram] since the knob extends out beyond the end of the homologous
chromosome and can't get apart of
[END PAGE FOUR]
[BEGIN PAGE FIVE]
chromatids stay together 2 by 2. This seems to be the case in the figures I have observed.
Have some nice dope and trivalent synapsis in early prophase. I know now that when a univalent part is present it shows double,
that is, shows the split. It is sometimes difficult to tell which is the 2-by-2 and which is the single part. Synapsis is
only 2-by-2 for any 3 chromosomes. There is something contradictory or not understood. All 3 of the satellite chr. are together
at the region which forms the nucleolus (the region) which is attached to the nucleoles [sic]. The chromatin part behaves
as the trivalents do. I am wondering if it is chromosomes or chromatids which synapse 2-by-2. Am working on this now.
People have been walking in and out our my room making such a disturbance I can't keep concentrated. My letter will probably
be quite uncoordinated. I hope you can make it out, though [?].
Will I see you in the fall? I hope so. There is so much to talk about besides business.