680 
Journal of Agricultural Research 
Voi. XXVIII, No. 7 
The chromosomes of Tripsacum dactyloides pair promptly at diakinesis of the 
pollen mother-cell, giving approximately 35 bivalents. 
In Tripsacum laxum , T. pilosum and T. lanceolatum the presence of both uni¬ 
valent and bivalent chromosomes at diakinesis makes the assigning of a definite 
haploid chromosome number difficult. This number, nevertheless, is approxi¬ 
mately 35. 
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