PLATE i 
Basal portions of petals of Pima cotton showing the range of grades in the spotless 
and normal families and in the hybrid between them. Grades o (fig. i) and 3 (fig. 2) 
represent approximately the extremes of the recessive populations, while grades 6 
(fig. 3) and 9 (fig. 4) represent approximately the extremes of the dominant populations. 
