2. The embryo culture technic was utilized to obtain hybrids of tetraploid corn and tetraploid Tripsacum. Tetraploid corn was pollinated with a mixture of pollen from 4n corn and 4n Tripsacum by stripping down the husks and sprinkling the pollen over the silks exposed throughout their entire length. The husks were then drawn up about the ear shoot and held in place with rubber bands and a glassine bag to prevent excessive evaporation. Ears pollinated in this manner were harvested 18 to 21 days after pollination, the embryos of the partially developed kernels were excised and transferred to a sterile agar nutrient medium in 2 oz. bottles. After their root systems were well established, usually after 10 days to 2 weeks, the seedlings were transplanted to soil. The 56 chromosome hybrids are slow-growing and thus far show no evidence of hybrid vigor. At the present time (January), 4n corn plants of the same age and similarly derived from excised embryos originating from pollinations made last August have passed the silking and pollen-shedding stage, while the hybrids are still making exclusively vegetative growth and show no evidence of stem elongation, although they are sturdy, healthy plants. Since these Tripsacum-corn hybrids, unlike those previously obtained by Mangelsdorf and Reeves, have two sets of chromosomes from each parent, they should be highly fertile; but this remains to be seen.