Meiotic behaviour in three different F1hybrids between maize andTripsacumis described. In the hybrid involvingT. dactyloides, a regular spindle formation was observed; however, the distribution of the chromosomes was quite irregular. There was no spindle formation at metaphase 1 in the hybrid between maize andT. floridanumand the meiotic process did not go beyond the first division. In the hybrid involving a maize strain with a reciprocal translocation (1–6) andT. dactyloides, very few spindles were noticed, but the chromosomes did not move towards the poles. Cytokinesis took place by furrowing without the division of the chromosomes. There was no definite association either between maize chromosomes and those derived fromTripsacumor between maize andTripsacumchromosomes themselves.