296 



Journal of Agricultural Research volxix.no. 7 



The yields of the original plots are shown in figure 7. These may be 

 combined in a 2 by i fold manner to give a correlation of 



f = 0.344 ±0.081, >'/£^r=4-25- 

 These rice yields taken from a field described as "extremely regular" 

 show that as a matter of fact the field is heterogeneous and that this 

 irregularity influences in a measurable degree the yields of the plots. 



Fig. 7.— Diagram showing yield of unhusked rice on Coombs and Grantham's 54 plots J^ by J4 chain 

 square. The yield is expressed in gantangs per plot. 



II. EAR CORN 



Smith {18) has published a series of corn yields for three years on 

 plots of Vio acre. The yields are given in his original paper. He has 

 kindly supplied the map showing the relative positions of these plots, 

 which are arranged thus : 



loi, 201, . 

 102, 202, . 



601 



602 



120, 220, . . . 



620 



