AMERICAN JOURNAL OF BOTANY 



[Vol. 8 



variability ranging from -4.7 to -8.0 percent. In line 139 the coefficient of 

 variation for trimerous seedlings is 5.47, whereas that for dimerous seedlings 

 is 3.48. In line 143, the coefficient of variation for trimerous seedlings is 

 10.01, whereas that for dimerous seedlings is 7.75. Thus the relative 

 variability in these two lines is greater in the trimerous than in the dimerous 

 seedlings. 



B. Intercalary Bundles. The distribution of the number of intercalary 

 bundles (considered alone) in the base of the hypocotyl is shown in table 5. 



LM 15 



L///E33 



FIG. 14. Percentage frequency distribution of number of intercalary bundles at base 

 of hypocotyl in dimerous (solid dots) and trimerous (circles) seedlings. 



The graphs in figure 14 show that for both dimerous and trimerous 

 seedlings no intercalary bundles is the modal condition. In both cases 

 the distribution is wholly skew. The normal and the abnormal seedlings 

 of lines 75, 93, and 98 differ conspicuously, however, in that the percentage 

 of seedlings with no intercalary bundles is much higher in the trimerous 

 seedlings, while, conversely, the percentage of seedlings with from I to 

 intercalary bundles is much higher in the dimerous plants. These 

 ferences are not found in lines 139 and 143. As a matter of fact, the per 

 centage of seedlings with no intercalary bundles is slightly, but perhaps nc 

 significantly, higher in the dimerous seedlings of line 139. In both line 

 139 and 143 the number of seedlings with i or 2 intercalary bundles is very 

 small indeed in both trimerous and dimerous series. The two lines are 

 essentially alike in this regard and line 143 only is represented on the 

 diagram. 



