PLATE 2 
Figures 1, 4, 6, 7, 8, 10 are from camera lucida drawings of F 4 segregates of 
Amby X Kubanka and correspond to the numbers of the segregates shown below. 
These figures are from pollen mother cells at the time of the first reduction 
division. 
Figures numbered 7 (M X A) are from segregate g of Marquis X Alaska 
shown in Plate 1. The side view of the heterotypic division shows the three 
lagging chromosomes soon after they have divided. 
F. 1-10.—Segregates of Amby X Kubanka F 4 . The numbers correspond to 
the chromosomes figures shown above and to the numbers shown in Table VI. 
The description, chromosome number, and degree of sterility of each of the segre¬ 
gates pictured are shown in Table VI. 
