Variation and Correlation of Oats — Part II 159 



There is a decrease in average height of plant in centimeters from the 

 least to the most crowded conditions'; the extreme differences being 16.802 

 centimeters in one line, and 16.583 centimeters in the other. As to 

 variability, however, the plants growing under the least crowded conditions 

 show the least variation, while those in intermediate conditions of crowding 

 show the greatest variation. This is true for both lines. 



The means for average length of head per plant m centimeters decrease 

 as crowding increases. In line 50 the variability decreases in like manner, 

 but the differences are slight. In line 62 the variability decreases in the 

 same order as does that for height. 



For average weight of kernels per plant in milligrams, the means decrease 

 in regular order from the least to the most crowded condition in line 62, 

 but the extreme difference is but 2.707 ± .125 milligrams. In line 50 

 the greatest weight occurs in series 63, the second greatest in series 122, 

 and the least in series 100, the intermediate condition of crowding. The 

 extreme difference here is 2.939 ± .184 milligrams. Variability is least 

 in both lines in the least crowded conditions, but the differences are not 

 great. 



The average number of kernels per culm of plant decreases markedly 

 as crowding increases; the extreme differences being 21.741 ± .576 for line 

 50, and 25.560 dz .606 for line 62. The variability likewise decreases 

 as the plants have less room. 



The average number of spike! ets per culm of plant should be considered 

 here, since it is so closely related to the number of kernels. The same con- 

 ditions exist for the two characters. The extreme differences in the 

 means for number of spikelets are 10.575 ± .292 for line 50, and 12.320 

 zt .292 for line 62, and the variability is also less as more crowded con- 

 ditions prevail. 



The average number of kernels per spikelet of plant should now be 

 considered. The differences here are small, but in both lines the mean 

 is highest when conditions of crowding are intermediate; it is lowest 

 when crowdmg is greatest in line 50, and at the other extreme in 

 line 62. Variability mcreases directly with crowding in line 50, but in 

 line 62 the plants in the intermediate condition of crowding have the 

 greatest variability, while the two extremes are practically the same. 



Three lots of data have been taken on the straw: the diameter, in 

 decimillimeters; the average weight of straw per culm of plant, in deci- 



