Ing. T. Angel Kate Y. Centro InternaciJnal de 1~Ie~oramiento de Naiz y Trig0 Londres 40 FI6xico 6, D.P. Dear K:ito: The Xerox copies of t:iin th:tt * you were inter mstcd in t#odcs under consi:,eration. 'i'hese topics were concened with our progress in detecting origins, migratio.:s, introductions, and introgressions of races of maize as revealed by the co::s-titution of the knobs that are J2resen-t in the chromosomes0 1t1`4e&""e evidex-it t'hzt relationships could be uncovered by t'his means. 'ihe results that Blumenschein has obt&jined in his studies find his arialysfs of knob constitutions of races of mG!iee r;,'ro;)qn in Venezuela, Brazil, raraguay, Bolivia, and Argentina, have proved striking confirr:i:i tLn of the correctness 05 the premises upon which the knob studies \:rere initiated. during our dis:ussions in piexico L>ity tests Of the validity of any one premise were undettakenjand with the dattt that were being organized at the ti:::e, either in table or map form. horn such organizations it ~8s possible to r eaognii:e the i,jreserh:e of dis ti;l-c tive knob co~~Iexes, to project their 0ri:;inal locations, to follo~w their migrati;3ns a,n(, their introgressions as TV\iell 5is to recognize their Katie - 2 - introductions into new ge0gra:shi.c loc:itions, &.rthermore, it owns $ossible to recognize specific routes of migration and introduction that had occurred in the past. You may recall that names s,lere attached to some of these routes, such as the "Centrl 1,lesa iioute", the !'Venezuelan Route!', n the com.Tlex but very well defined "sapnlote Chico lioute", etc. w I have reviewed the c oztent 0-f these discusoi:):ns A in order to emphasize what I have always cor,sitiered to be the l;rimary goals of the knob studies. aLPhe analyses that I have conducted ;Cth the knob data have always focused on these goals; and the results have served to confirm, supplement, and extend the conclusions of Wellhausen et al. S~x$k~ixx~~~m~w$ (1952) on the origins and rel:ttion- ships of the races of mrli:ze, 3ecause of the prominence of m:'ize 2s an economic plant and because of its extraordinary and s OCI ewhst hidden history, attempts to elucidate its origins are of particular significance, --or so I believe, I have some serious thoughts with regard to the manner of organization of the data that appears in yo;lr charts and tables. Xlthoilgh these charts and tables show so:r:le types of relati:nsilips they are unclble to reveal why the results nopear as they do within any o prearranged geographic boundary. The proportion of individual knob types that apuear within 'iny one bound area will depend, in many instances, on the num:Jer of plants of any one collection or of any one race that had been examined. i?or exampleq,tif rbne had examijied many plants of the race Cacahuacintle and few plants of the race G6nico, one conclusi:ins might have been drawn from the charts and -t.ii?les. examined plants of nad the propo:'tion of,these two races been reversed, another tiesults would have been obtained and another conclusion could have been drawn from it. Again, it is clear that the maize of the Kiowa and the ~~~escalero tribes of Oklahoma have knob cozistitutions that link this ie Kato - 3 - maize closely with that of the Apache and Bdvajo tribes in Arizona and i\jew Lexico . Iiiaize from other tribes in Uklahomn, and in st:ltes to the north of Oklahoma, show similar linkage but this maize has been diluted to a much greater extent by introgressions with maize that w,as being grown in the North Gentral states of the ii.3. Erom the chromosome constitutions of the sampled maize in all of these sttites, it is possible to reconstruct the types and locations of the knobs that were present in the maize of the North Cen%ral U.3. This m:iize :t?;,ears tJ have had its origin either in the dentr;l Mesa of Xexico or the Highlands of Guatemala, There a:`e some other illustrations that reflect the need for caution in lumping data aocording to a preselected geographic boundary. :L good example wocrld be that of the large knob in the long arm of chronosome 9 in Costa Rica. It is confined to a clearly defined PQti* area in North Central tiosta Rica and it is present innevery examined collection within that area. Although it is prcdsent in Yanama, it is not present in the examined oollections from Nicaraguap nor in any other collection from Costa Rica. This is a revealing observation that lt;mped data would obscure. it should nut be so lost. Rather, it shotAd be recognized for its value>and the reasons for its si:-+ul:ar 2 distribi!tion shoiild be sought, iinother example of this type is ex_:,ressed in soiithern Bolivia and it involves the race r'erola. 'Yhi s race is most singular for the area because in h:is all of the large knobs that characterize the "Venezuela-Southern tiuatemala" corn;~iex. _ Obviously, it has relatL7ely been Ctrofiuced into the area oniy,recently. S oine 0 f other races of its knobs h,lve migrated into,maize in its vicinity but others hrive not. Lumpted data x.or the area in which this race a.:?l,ears w:uld no-t reveal the true source of the large knobs distribute TcJit:?in it. Kato - 4 - I am distrubed by another as;;ect of organization of yo;.lr da ta. You give percentage figures for the frel::ency of occu,'rence of large, medium, and small knobs, as well ~1s no knobs, at the partic,:lar locations in erich of the chro!:loso es, km calcuhted from data of Longleg and &to. Because these data do not include the knob co;:stitution of each homologue, a me2ningful percentage figure for frequency of knob type may not be obtained from them. As calculated, some of the percentages may be close to accllrate whereas others may be quite inaccurate. These data, nevertieless, do allow certain deductions to be drawn even though they do not permit accurate quantitation, After receiving your tables and ch`lLrts, I be&:in to fill in illank m ips 0 - the Americ ns, both North 2nd South, in order to illustrate where specific knobs are located, the &b~&xx~a$ix distinctive ;Da-tt-?rns of distribiition that are shown by the diffevaent knobs, the knobs th,+t sh:ire the same patterns of distribution, and, wilen indicated, the partic:!lt:r race or r,?ces of maize thrzt ~s~xxcw$mx hiive followed one soecific mQratory path, You may recall that this method of @otting the data !~ras employed at our November 1966 meeting. Because this method m:Lkes it possible to reconstruct many facts relatirq; Co the past history of the races, it was the reason for all of the effort that you and Blumenschein put in last summed in constructing such ma&es %!X~XIIB;I with the data obtail!ed from the 1;lexican collections. 1 do not know in what way you have used these maps, but for me thay have been invaluable. TO illustrate this, I am enclosing a summary statement on the origin and distribution of knobs of medium size that I hastily put togethL-r to send to you, Some shift in emphasis mty n.:ed to be made subse iuently but this should not upset the general thesis as outlivled in the statement. 1-t is too stroilgly supported by the d:ita,. ' Will conclude by stating that Slumens,>hein has used th$s" same methzd GIL-to - 5 - 8~ annlysing the sources of the maize riii:es he hz investigated. AS I stated earlier, he has been able to formulated some very defnite conclusitins / the origins, migrations, ^.._ introgressions, and introductions of maize in the areas of his studies> In this long letter, * have outlined in soze detail my Iroints-of- pleased view, and why I hold them. 1 should be @ati to know your reaction to them, If you cannot agree that these points-of-view have value for you, I should be grateful to be so informed, Sincerely yoldrs, Barbara lW3intock.