110 Clyde E. Leighty 



it being 14.000 dz .330. Series 1238 has the greatest amount of varia- 

 bility, however, the standard deviation here being 10.834 ± .298, while 

 that nearest to it is 9.230 ± .254 for series 1219. The smallest standard 

 deviation is 7.082 ± .195, for series 1200. 



Since the means of nmnber of spikelets are not proportional to the means 

 of average jaeld, the same conclusions hold as were made when number 

 of kernels was discussed. And again, since the means for number of spike- 

 lets are not directly proportional to those of number of kernels, it follows 

 that the average nmnber of kernels per spikelet must vary for different 

 varieties. These values have not been determined from the original 

 data, but it is e\ddent from the means here determined that the Sixtj^ 

 Day oats have the largest number of kernels per spikelet and that the 

 Early Champion oats have the smallest number. The remaining varieties 

 have numbers of kernels per spikelet somewhere between these two. 



The means for average weight of straw per culm of plant in decigi'ams 

 follow the same order of value as do the means for average yield of culm 

 per plant in decigrams. Series 1238 has the largest mean, 9.767 ± .204, 

 while series 1219 has the smallest, 5.227 zb .107. For series 1200 and 

 1257 the means are 8.653 ± .180 and 5.303 ± .116, respectively. The 

 standard de^dations agam follow the same order as do the means, 

 being greatest m series 1238 and least m series 1219. 



While there is a definite rise and fall in the means of the average weight 

 of straw per culm of plant with increase and decrease in the means of 

 the average jdeld of culm per plant for the different varieties here con- 

 sidered, the proportion of grain to straw is not the same for each variety. 

 Considering the mean for average jneld of culm per plant as unity in each 

 case, the mean of average weight of straw per culm of plant is in the 

 following proportions for the different varieties: 



Great American 1 : 1 . 35 



Early Champion 1 : 1 . 52 



Welcome 1 : 1 . 19 



Sixty Day 1 : 1.34 



As the average yield of culm per plant mcreases, the proportion of straw 

 to grain decreases for the different varieties, with the exception of the 

 Sixty Day variety. In the Welcome variety the proportion of straw to 

 grain is lower than in any of the others. It seems to be a varietal character- 

 istic of the Welcome to produce less straw to the unit amount of grain. 



