56 Nebraska Agricultural Exp. Station, Research Bui. 6. 
12 3 4 5 6 7 8 9 10 11 12 
Fig. 11. — Representative plants grown in potometers of different sizes, with- 
out and with manure, to determine the effect of the size of the potometer 
as a source of experimental error in pot experiments. 1914. Reading 
from left to right: 1, potometer 12"xl2", without manure; 2, with ma- 
nure; 3, potometer 12"x24", without manure; 4, with manure; 5, poto- 
meter 16"x24", without manure; 6, with manure; 7, potometer 16"x36", 
without manure; 8, with manure; 9, potometer 21"x36", without manure; 
10, with manure; 11, potometer 30"x36", without manure; 12, with 
manure. See Tables 4 to 7. 
