fcb., 1921] HARRIS AND OTHERS SEEDLINGS OF PHASEOLUS 



97 



The variability of bundle number, both absolute and relative, is far 

 gher in the abnormal (trimerous) plants. The relative differences show 

 dat the trimerous plants are from 84 to 217 percent more variable than 

 ae dimerous in the number of bundles in the central region of the epicotyl. 



We now have to consider the relative number of bundles in the hypocotyl 

 nd in the epicotyl of the same plant. The constants for the normal plants 

 re shown in table 17 and for the trimerous seedlings in table 18. 



r \BLE 17. Comparison of statistical constants for number of bundles in hypocotyl and epicotyl 

 of same plant. Seedlings with two cotyledons and two primordial leaves 



Normal and abnormal plants have in common a larger number of bundles 

 n the epicotyl. The differences between the means for the two organs are 

 learly significant in comparison with their probable errors. The per- 

 :entage differences show that the epicotyl has from 15 to 50 percent more 

 mndles than the hypocotyl. 



In the dimerous seedlings the variabilities, both absolute and relative, 

 is measured by the standard deviation and coefficient of variation, are 

 -onsistent in indicating a higher variability of bundle number in the hypo 

 cotyl. The difference is, however, very slight in line 139. 



The difference between the variability of the hypocotyl and that of the 

 ipicotyl in the normal seedling as measured in terms of the standard devia- 



