The Regional Adaptation of Corn in Nebraska 
49 
represent extreme conditions, and it is believed that by such 
comparison, structural differences due either to hereditary 
adaptation or to mere environmental adjustment, may be de- 
termined. (Tables 26-28.) The methods of sampling and 
technique were the same as previously described. Seven hun- 
dred and twenty transectional leaf measurements, and one 
thousand epidermal counts and measurements were made for 
each of the eleven corn types grown in Lancaster and Kimball 
Counties, respectively. 
Comparing eastern, central, and western Nebraska types 
when grown in Lancaster County we have the following relative 
leaf values: (1) Leaf thickness, 100, 108, and 104; (2) average 
epidermal thickness, 100, 100, and 103; (3) thickness of cuticle, 
100, 101, and 98; (4) number of vascular bundles per unit of 
cross section, 100, 95, and 100; (5) number of stomata per unit 
area of epidermis, 100, 101, 97 ; (6) length of stoma. 100, 100, 
and 100; (7) length of stomatal aperture, 100, 94, and 90: (8) 
length of epidermal cell, 100, 93, and 94; and (9) width of 
epidermal cell, 100, 100, and 104. 
Corresponding relative values for corn grown in Kimball 
County were: (1) Leaf thickness, 100, 89, and 95; (2) average 
epidermal thickness, 100, 97, and 96; (3) thickness of cuticle, 100, 
98, and 98; (4) number of vascular bundles per unit of cross 
section, 100, 103, and 101; (5) number of stomata per unit area 
of epidermis, 100, 104, and 102; (6) length of stomata. 100, 
101, and 98; (7) length of stomatal aperture, 100, 101, and 96; 
(8) length of epidermal cell, 100, 100, and 100: and (9) width 
of epidermal cell, 100, 95, and 100. 
As an average for corn grown in both Lancaster and Kim- 
ball Counties the respective relative values for eastern, central, 
and western Nebraska types were: (1) Leaf thickness. 100, 96, 
and 100; (2) average epidermal thickness, 100, 99, and 100; (3) 
thickness of cuticle, 100, 100, 98; (4) number of vascular bundles 
per unit cross section of leaf, 100, 99, and 100; (5) number of 
stomata per unit area of epidermis, 100, 102, and 99; (6) length 
of stomata, 100, 100, and 99; (7) length of stomatal aperture, 
100, 97, and 93; (8) length of epidermal cell, 100, 97. and 97; 
and (9) width of epidermal cell, 100, 97, and 102. 
To determine the effect of the environment only upon the 
corn leaf structure, we may compare the mean results of the 
twelve types grown in Lancaster County as against the same 
corn grown in Kimball County. The relative values based on 
Lancaster County as 100 per cent are: (1) Leaf thickness, 100 
and 87; (2) average epidermal thickness, 100 and 91: (3) 
thickness of cuticle, 100 and 97 ; (4) number of vascular bundles 
