As Kihara had only I to 3 accessions of each diploid analyzer species in his germplasm collection, WE conclude the genome formulae for Aegilops and Triticum published by him between 1920 and 1960 were largely based on the typological concept applied to cytogenetic research. The same restriction applies to his concept of “modified genomes” in the tetraploid Aegilops species, which therefore may not actually be modified. Genome analysis by itself is not a very fine-tuned experimental technique. A biological specier concept based on several different biosystematic studies in Aegilops and Trificurn is preferable to a species concept based only on genome analysis in meiocytes of F, hybrids. Biosystematic studies recognize Aegilopa sharonensis, Ae. peregrinu, and Triticum urarfu as valid species distinct from other species. Our attempts tc resynthesize tetraploid wheats using Ae. spelfoides and Ae. searsii as female parents and T. monococcum and T. urarfu as male parents met with little success. There may be an embryo lethality mechanism operating in these F, hybrid combinations. Sterile hybrid plants were obtained with Ae. longissima, Ae. shuronensis. and Ae. bicornis as female parents in crosses with the two Trificum species as males. Amphidiploid seed was obtained with the use of colchicine.