220 
AMERICAN JOURNAL OF BOTANY 
[Vol. io. 
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EXPLANATION OF PLATE XXIII 
The optical apparatus used consisted of cardioid condenser (Zeiss), 1.8 mm. achro¬ 
matic oil-immersion objective (Spencer), and 10 X ocular (Spencer). In the figures a camera 
lucida (Bausch and Lomb) was used in drawing the outlines and indicating the general 
regions of the cell content. Details were drawn free-hand. The magnification of the figures 
is approximately 810 diameters. 
Fig. 1. Root hairs of wheat grown for one week in the following solutions: A, solution 
1. B , solution 2. C, solution 3. D , solution 4. E, solution 5. 
Fig. 2. Root hair of wheat, showing the effect on the protoplasm of a 0.45 M solution 
of hydrochloric acid in pure water. A, immediately after being mounted in the solution. 
B , at the end of \ hour. C, at the end of i§ hours. D, at the end of 2\ hours. E , at 
the end of 5 hours. 
Fig. 3. Root hair of wheat, showing the effect on the protoplasm of a 0.45 M solution 
of sodium chloride in pure water. A, immediately after being mounted in the solution. 
B, at the end of 5 hours. 
Fig. 4. Root hair of wheat, showing the effect on the protoplasm of a 0.45 M solution 
of nitric acid in pure water. A, immediately after being mounted in the solution. B, at 
the end of 1^ hours. C , at the end of 3^ hours. D, at the end of 4^ hours. 
Fig. 5. Root hair of wheat, showing the effect on the protoplasm of a 0.45 M solution 
of nitric acid in culture solution 2. A, immediately after being mounted in the solution. 
B, at the end of i| hours. C, at the end of 4 hours. D, at the end of 5 hours. 
