Variation and Correlation of Oats — Part II 109 



The means for average height of plant in centimeters vary among them- 

 selves less than for the character just considered. The mean for series 

 1238 is again the highest, being 62.916 ± .507. Series 1200 is again 

 second highest, being 56.533 ± .362. The order of series 1219 and series 

 1257 is reversed, the former being here 55.850 ± .432, which is considerably- 

 larger than 49.566 ± .416, the mean of the latter. The short plant of 

 the Sixty Day variety is without doubt a varietal characteristic. It seems 

 likely also that the means for height of each of these varieties denote 

 varietal differences. The greatest A^ariability is again m series 1238, as is 

 indicated by the standard deviation of 13.041 d= .359. The least variability 

 in height occurs in series 1200, where the standard deviation is 9.304 ± .256. 

 The short-culmecl variety, the Sixty Day, has a standard deviation of 

 10.703 ± .294, and for series 1219 the standard deviation is 11.114 ± .306. 



In average number of kernels per culm of plant the means of the 

 different varieties are not far apart in value. The highest, 30.213 d= .755, 

 is again for series 1238. The lowest, 26.387 ± .510, is for series 1200. 

 Series 1219 is second in order, with a mean of 29.293 ± .695, and series 

 1257 is third with 28.440 ± .663. The standard deviations for the four 

 series follow the same order of value as "do the means, the largest being 

 19.420 ± .534 for series 1238 and the smallest 13.113 ± .361 for series 1200. 



It is seen that the large differences do not exist in the means for number 

 of kernels that exist in the means for yield, neither do the means follow 

 the same order in amount. It is evident, therefore, that increase in yield 

 is not due to a larger number of kernels per culm. The average yields 

 per culm are more nearly proportional to the average weight of kernels 

 per plant. By examining the means of the latter character it is seen that 

 series 1238 has much the largest kernel, the mean being 25.413 ± .155. 

 The mean for yield of the same series is also considerably above the means 

 of the other series. The same condition exists throughout. Series 1219 

 has the smallest mean for yield and also the smallest mean for average 

 weight of kernels, the latter being but 10.913 ± .115. The greatest 

 variability, however, is in series 1200, where the standard deviation is 

 4.417 ± .121. The least variation is in series 1257, where the standard 

 deviation is 2.400 ± .066. 



The means for number of spikelets do not follow the same order of value 

 as do the means of yield and average weight, neither is the order that of 

 the number of kernels, although it is nearer the latter. Series 1219 here 

 has the largest mean, it being 17.160 ± .359. Series 1257 has the smallest, 



