30 
Nebraska Experiment Station Research Bulletin 19 
preceding morphological adaptations, the morphological char- 
acters for these seven counties only are briefly summarized in 
Tables 14 and 15, in order that the histological data may be 
directly comparable with them. 
Fig. 10 — Microphotograph of a cross-section of corn leaf, showing arrange- 
ment of vascular bundles, relative epidermal thickness, cuticle, and stomatn. 
Enlarged 233 diameters. 
In comparing native types grown under the two extreme 
conditions of Richardson County and Kimball County, it is ob- 
served that whereas the plant weight and leaf area of Kimball 
County corn are only 34 and 30 per cent as large respectively, 
the relative thickness of the leaf, and upper and lower epi- 
dermis are respectively 96, 97, and 97 per cent as great. The 
proportion of epidermal thickness to total leaf thickness is almost 
identical for both extreme types. The number of vascular 
bundles in one centimeter of cross-section of leaf is 1 per cent 
