56 BULLETIN 754, U. S. DEPARTMENT OF AGRICULTURE. 
It becomes of interest to note that there is one other case where a 
plant heterozygous for two color factors when pollinated with pollen 
from a plant heterozygous for one color factor and homozygous for 
the other has a percentage of white seeds intermediate between 25 
and 43.75. The ears are Nos. 1933 and 1935, Table XXV. The plant 
that bore these ears also bore ear No. 1934. The ear numbered 1935 
had for a male parent the same plant which served as the male parent 
of No. 1933. Both of these ears had white seeds in excess of the 
expected. Ear No. 1934 was the result of self-pollinating the female 
parent of ears Nos. 1933 and 1935. This self-pollinated ear had 46.6 
per cent of its seeds white, demonstrating the plant to be heterozy-. 
gous for two color factors. 
The male parent of ears Nos. 1933 and 1935 produced an ear the 
result of self-pollination, No. 1912. This ear had 24.9 per cent of its 
Fed /860 1874 1875 18760 
Fic. 6.—Diagram showing the relations of ears Nos. 1860, 1874, 1875, and 1876. 
seeds white, demonstrating the male parent to be approximating the 
percentage expected if the plant were heterozygous for one color 
factor and homozygous for the other. 
A reciprocal cross was also made between the plant which pro- 
duced ears Nos. 1933, 1934, and 1935 and the plant which produced 
ear No. 1912. The ear representing the reciprocal cross of ears Nos. 
1933 and 1935 is No. 1911. This latter ear had 26.6 per cent. of its 
seeds white, the deviation from 25 per cent being only slightly in 
excess of the probable error. The difference between the reciprocal 
ears (averaging Nos. 1933 and 1935) is 4.1 per cent, a difference that 
would be expected as the result of chance once in six times. The 
relations of these ears are shown in figure 7 . 
The seeds from three ears, Nos. 1876, 1933, and 1935, were re- 
examined and the classification was found to be correct. The dis- 
tinction between white and colored seeds was very good, no doubtful 
seeds being encountered. Ears Nos. 1876, 1933, and 1935 indicate 
