August 9, 1946.         .           .

Dear Dr. Dubos:

   In connection with our exprimente on the oacurrence of secombination

genotypes in mixed cultqs of bacteria, I am trying to review past experixmn$m

on `hybridization'of bacteria. Your monogmph, The Bacterial Cell, hns been
highly ueeful in this projict. However, there seem to be an implication on
p. 181 that you may have other references tol whioh you did not think impor-

tmb enough to record:

   ( Although them have been isolated reports of succeeaful orosrring,

most workers who have attempted to 01'0s s related stralna have reported only

failure...'

   Only three papers have conrp to ~qy attention on this aspect:

Ahnquiet,l924, Sherman and Wing 1938 and Gowen and ticoln 1942.

   I would appreciate it very much if you would send llhe any other

references of euch experiments, whether successful or not.

                        Very sincerely yours,

Joehua tide&erg.