Nebraska Experiment fetation Research Bulletin 10 
36 
significant histological adaptation. Practically speaking, the 
types adapted to the driest one-third of the State have de- 
veloped no less succulent leaf, and no thicker epidermis result- 
ing in reduced opportunity for water evaporation. The actual 
number of stomata per square millimeter is 14 per cent greater 
for western than for eastern Nebraska corn. This would seem 
to increase the opportunity for evaporation. 
However, the greater number of stomata would seem to be 
offset by a reduction of 10 per cent in length. The fact that this 
10 per cent reduction in length of stomata is accompanied by a 
13 per cent reduction in length of the epidermal cell, which re- 
duction would in no way be associated with water economy, 
Fig. 12 — Native corn types from nine regional areas of the state, grown com- 
parably in southeastern Nebraska. (Lancaster County.) 
Each group of ears is the harvest from ten successive representative plants 
of each type. The seed from all sources matured well when grown in Lan- 
caster County. 
(1) Thurston County corn, (2) Lancaster County corn, (3) Richardson 
County corn, (4) Holt County corn, (5) Kearney County corn, (6) Nuck- 
olls County corn, (7) Cherry County corn, (8) Kimball County corn, (9) 
Lincoln County corn. 
suggests that neither this stomatal shortening nor increased num- 
ber of stomata per unit area are adaptive in nature. They are 
perhaps rather the combined result of less favorable growth 
conditions and of an inherent smaller cell development which is 
associated with the smaller plant growth habit of the earlier 
types. 
