ee eee ee ee ——— ee 
60 BULLETIN 754, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE NXVI—Possible effect of self-fertilizing a plant in which the color 
factor has become fractionated in such a way as to make the union of the 
gametes result in a colored zygote. 
[The percentage of white seeds is 39.06.] 
Gametes. | CR. | CR’. | Cr. | Cr. | cR. | cR’, | ete | cr. 
Cheats. = 2 Colored. .| Colored - : Colored...) C pioedicl Colored. .| Colored. | Colored - | Colored 
COR eee ls do fe Palen a ee Hig ees kc art-ria tet et. pees or | Do. 
(Co See, See ee ee ee White...|...do Bae AE hem iene | -White 
Cap eee Be doses al doe sl Wee as eee bere | White...| Do 
el Pe SS ae ea |_..do | ~2d0:2-- | Ghiored | Colored... White... White. ...|...do-_....- | Do. 
CR See eae eee: gee ae rele S AGORNeCe Ss does Vexde wee. beagles ees | Do. 
Chit cee se en ale do doze.a2 White ..|...do. | dose" ee Pat ehe! | Do 
Chere ae si dOs-2222 White doz: |...do. | dos Seaas do: 2.23 | Do. 
The other aberrant ear, No. 1914, which is shown in figure 9, is a 
very close approximation of the 1 to 1 ratio, the deviation being but 
slightly in excess of two times the probable error. The deviation is 
also insignificant from the 56.25 per cent white expected on a 7 to 9 
ratio, while the expected ratio was 9 to 7 or 48.75 per cent white. 
Here again we may be dealing with a fractionation of the factor R ~ 
in such a way perhaps that enough has been separated from the fac- 
tor # to occasionally prevent the normal color reaction with the 
Colored 
Nek! dns cae 
Fed. /9/F¢ 19/5 19/2 
Fic. 9.—Diagram showing the relations of ears Nos. 1914, 1915, and 1912. 
expected percentage of white seeds is 53.1, which is indeed a very 
close approximation to the observed 53 per cent. 
With the assumption that the plant which bore ear No. 1914 was 
of the type indicated in Table X XVII, such a plant if crossed with ~ 
one heterozygous for the factor C and homozygous for the normal — 
R factor would give an ear with the monohybrid ratio of white to 
colored seeds which fits the observed results, as is shown in figure 9. 
factor C. (See Table XXVII.) If this assumption is made, the { 
