Experimental Error in Croj) Tests 
83 
1 2 3 i 5 ij 7 8 9 10 1 
Fig. 17 — Crop harvested from pots of six different sizes, 1915 (Table 
41 j. One plant was grown per pot, with four pots of each size. 
Odd numbers without manure, even numbers with manure. (Ma- 
nure added in proportion to soil contents.) 
Pounds of soil, left to right: 1 and 2 — 920 lbs.; 3 and 4 — 561 lbs.; 5 
and 6 — 253 lbs.; 7 and 8 — 161 lbs.; 9 and 10 — 83 lbs.; 11 and 12 — 
3 6 lbs. 
