700 Journal of Agricultural Research v«i. xxi, n«. io 
the same result as Aa. If the classes AA and Aa be taken as one, the 
deviation from expectancy is two, which is less than one-lialf the stand¬ 
ard deviation. 
An examination of the diseased plants revealed an interesting pheno¬ 
menon as illustrated by Plate 135. Those plants which were awned 
segregates of the class in which part of the spikes were diseased showed 
normal development of the awns in the disease-free spikes and a sup¬ 
pression of awns in the diseased spikes. No spikes were found which 
contained both diseased and disease-free kernels. 
