No. 624] INHERITANCE OF HULL-LESSNESS 13 



mediate types reproduced the three types again. The 

 second generation plants tested as to their composition 

 gave the following results in the third generation : 



111 j Hulless X Black Tartarian | 37 j 85 



51 j Danish Island X Hulless | 115 j 216 



152 i 301 I 152 



It is apparent from these results that certain plants were 

 classed as intermediate in the second generation, which 

 were in reality pure hulled plants. It is evident that the 

 huUed-huU-less character is inherited in a simple Men- 

 delian fashion so far as its general behavior is con- 

 sidered. 



The heterozygous plants produced in the third gen- 

 eration were examined as to the relative amounts of 

 hulled and hull-less kernels present. This was done by 

 threshing a representative head from each plant by hand 

 and counting the hulled and naked kernels and express- 

 ing the result as the percentage of hulled kernels. 



In order to determine whether the results irom a 

 single head fairly represented the type of the plant a 

 number of plants w^ere examined and recorded a head at 

 a time. The percentage of hulled kernels for a represen- 

 tative head was then compared with that for the entire 

 plant. The average percentage was the same for the 

 results from single heads as it was for the entire plant. 

 Although there was some deviation in the individual de- 

 terminations, the correlation betw^een the two methods is 

 very high. 



The result of determining the percentage of hulled 

 kernels was to indicate tlie uicat xnriation existing, 

 which was from a very low to a very high percentage. 

 As a result of these observations it was apparent that 

 while in the hybrids under consideration the usual 1:2:1 

 ratio was observed, some factor or factors were pres- 



