in maize were encountered at least once. In addition three 
positions not previously reported, two on the long arm 
of the tenth and another terminating the short arm of 
the first chromosome, were seen bearing enough pycnotic 
material to require their being classed as knobs. 
Table I shows the departments and localities from 
which the varieties were collected; the range in knob 
numbers and average knob numbers. The thirty-eight 
localities and their average knob numbers are also shown 
in the accompanying map. 
‘The average knob number for the 162 varieties is 7.9, 
the highest average number so far reported for any coun- 
try or region studied. Even without further analysis this 
bears out the assumption that the highest knob numbers 
should occur in the general region where teosinte is most 
abundant in the wild state. 
The second and somewhat contradictory assumption 
that varieties with knobless chromosomes might also be 
encountered in this same general region has not been 
completely met, although it has been closely approached. 
Three varieties were found with only one knob and it is 
reasonable to suppose that knobless plants would have 
been discovered in these or other varieties had additional 
studies been possible. Indeed Dr. R. G. Reeves, working 
with other samples from Guatemala, has found one vari- 
ety segregating for knobless plants. 
Of particular interest is the knob situation in the De- 
partment of Huehuetenango. In a small area of less than 
two hundred square miles, approximately the area bound- 
ed by a polygon in which the points are formed by the 
localities of San Antonio Huista, Santiago Petatan, San 
Martin Cuchumatan, Todos Santos Cuchumatan, San 
Juan Ixcoy, Santa Eulalia, San Sebastian Coatan, San 
Miguel Acatan and Jacaltenango, are found knob num- 
bers ranging from one to fourteen. Here in an area scarce- 
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