"Organized by the Czechoslovak Academy of Sciences under the patronage of Genetic Section of the I.U.B.S., Czechoslovak National Commission for U.N.E.S.C.O., I.A.E.A., and C.I.O.M.S." One paper in French. One of a series of symposia held on the occasion of the centennial of the publication of G. Mendel's Versuche über Pflanzenhybriden.
