INHERITANCE OF WAXY ENDOSPERM IN MAIZ&. 59 
question were homozygous for the same color factor and heterozygous 
for the other. The percentage of white seeds is a fairly close 
approximation of 31.25 per cent expected on a 11 to 5 ratio, but the 
assumptions necessary to account for this ratio on ears that result 
from self-pollination are too absurd to permit such an explanation. 
The relations of these ears are shown in figure 8. 
Here again we have evidence of a change in the effect produced 
by the factors, but since the same plant behaved normally when 
crossed with a sister plant in respect to both male and female 
gametes we must assume that whatever the change it was not suf- 
ficient to affect the results except where the changed gamete was 
received from both parents. 
If we look upon ear No. 1862 as being a deviation from a 
dihybrid ratio, there is an excess of colored seeds. If the assumption 
UAE AVALN | /86/ /87/ 
Fie. 8.—Diagram showing the relations of ears Nos. 1862, 1861, and 1871. 
is made that this excess is due to a fractionation of one of the 
factors, this altered factor must be the one for which the plant 
which bore No. 1871 was homozygous. 
Thus the plant which bore ear No. 1862 was forming gametes 
CR, Cr, ck, and cr. If we assume that a sufficient amount of the 
factor 2 was included in the gamete C7’ to make the union of the 
two gametes C7’ result in a colored zygote the ratio of white to 
colored seeds would be altered and the percentage would be 39.06 
white, a percentage closely approximated by ear No. 1862. (See 
Table X XVI.) This change, however, was not sufficient to produce 
color when combined with a pure C7 gamete obtained from the sister 
plant, as is shown by ears Nos. 1861 and 1871. 
