10 BULLETIN 1341, U. S. DEPARTMENT OF AGEICULTUEE 
such close selection. It probably is safer also to avoid close selection 
for any other characters unless the}^ are known to be associated with 
productiveness. In any event, the emphasis that is placed upon uni- 
formity of sample in corn shows seems unfortunate if it is to h(^ 
taken as indicating the desirability of having a variety of corn with 
uniform ears. 
SUMMARY 
Six strains of corn differing in the number of kernel rows on the 
ears and the indentation of the kernels were isolated by mass selec- 
tion from C. I. No. 119, a strain of Boone County White. The pro- 
ductiveness of these strains and of crosses between them was com- 
pared with that of the parent variety. 
All of the selected strains yielded less than the parent variety. 
The strains which departed less from the characteristic condition of 
the parent variety with respect to number of kernel rows tended to 
be more productive than those that departed more from the char- 
acteristic condition of the parent variety. 
The crosses between selected strains ranged from about 15 per 
cent less productive to about 5 per cent more productive than C. I. 
No. 119. 
There was a direct relation between the productiveness of the 
individual crosses and the number of kernel rows by which their 
parent strains differed. This fact was interpreted as indicating that 
the selected strains were more or less homozygous for the different 
combinations of genetic factors determining the different numbers 
of kernel rows. 
On this basis, close selection for a specific kind of ear would tend 
to bring about a homozj^gous condition of the factors necessary for 
that kind of ear, and decreased vigor and productiveness similar to 
that caused by inbreeding would follow. 
In view of the lack of evidence of marked consistent superiority 
for any particular kind of ear, it is unfortunate to teach that uni- 
formity among the ears of a variety of corn is desirable by attach- 
ing importance to uniformity of sample, as is done in corn shows. 
