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THE AMERICAN NATURALIST [Vol. LIII 



borne out by the fact that in series 51, where over 900 

 plants of the third generation were sorted into the dif- 

 ferent classes, there was no indication of a grouping near 

 the middle classes, in fact, the slight indication of group- 

 ing was near the lower values. The distribution is as 

 follows : 



TABLE II 



Showing Peecentage op Hulled Kernels in the Heterozygous Plants 

 OP the Third Generation in a Cross Between Danish 

 Island and a Hull-less Oat. 



It was planned to carry some of this work further to 

 answer in general two questions which are: (1) Does the 

 percentage of hulled plants obtained from any hetero- 

 zygous parent vary with the percentage of hulled kernels 

 possessed by that parent? (2) Do the hulled and hull- 

 less kernels of a heterozygous plant give approximately 

 the same results in their offspring? 



In order to obtain data on these questions two of the 

 series have been continued. The huW-less- Avena fatua 

 series has not been carried further as yet but it is 

 planned to do so. 



Results from Series 202— Swedish Select X Hulless 

 The first series to be discussed is the Swedish Select- 

 Hull-less cross. Seed from two hulled and two hull-less 

 plants of the second generation were grown in the third 

 generation and each bred true to type. In addition to 

 these plants twenty heterozygous plants were selected 

 for planting. These varied as to the amount of hulled 



