Corn Investigations 
85 
Table 32. — Immediate effect of foreign 'pollen upon kernel weight 
of an ordinary variety of dent corn. Five years , 19 H~ 19 17 
and 1920. 
Year 
Kind 
of kernels 
Number 
of kernels 
in test 
Weight of 1000 kernels 
(moisture free) 
Difference in 
weight of 1000 
Actual 
Relative 
(1) 
(2) 
(3) 
Grams 
(4) 
Per cent 
(5) 
Grams 
(6) 
Per cent 
(7) 
1914.. .. 
Pure 
| Hybrid 
5,000 
5,000 
307.8 
313.4 
100.0 
101.8 
+ 5.6 
+1.8 
1915.. . . 
Pure 
Hybrid 
10,177 
10,177 
246.1 
249.3 
100.0 
101.3 
+3.2 
+ 1.3 
1916.... 
Pure 
Hybrid 
9.405 
9.405 
272.0 
271.5 
100.0 
99.8 
—0.5 
—0.2 
1917.. .. 
Pure 
Hybrid 
8,435 
8,435 
281.7 
279.8 
100.0 
99.3 
—1.9 
—0.7 
1920.. J 
Pure 
Hybrid 
5,000 
5,000 
259.6 
257.8 
100.0 
99.3 
i 
—1.8 
—0.7 
As a five-year average, the hybrid kernels weighed 0.32 per cent more than 
the pure. 
The hybrid kernels were Hogue’s Yellow Dent fertilized by Nebraska White 
Prize corn. 
The pure kernels were Hogue’s Yellow Dent. 
This is equal to one bushel increase in every 312 bushels hybrid 
grain. The data suggest that the gametes which unite to pro- 
duce the kernels within an ordinary variety of dent corn are 
already so unrelated that the vigor which they impart is only 
very slightly exceeded by introducing foreign Mendelian factors 
thru the pollen of another dent variety. This conclusion is fur- 
ther substantiated by the data for 1921 with miscellaneous varie- 
ties, in Table 33. As an average for five varieties fertilized in 
part by foreign pollen, the hybrid kernels weighed 0.42 per cent 
heavier than the pure kernels. 
RESULTS WITH PURE LINES AND VARIETIES COMPARED 
In 1921 the immediate effect of foreign pollen on kernel 
weight was determined for the following combinations: (1) 
Pure line (inbred) Hogue’s Yellow Dent ears fertilized by a 
mixture of pollen from pure line sister plants and from Ne- 
braska White Prize pure lines. (2) Pure line Nebraska White 
Prize ears fertilized by a mixture of pollen from pure line sister 
