Tov., 1921] 



HARRIS AND OTHERS PHASEOLUS VULGARIS 



429 



It is suggestive to note that the negative correlation between number of 

 &amp;gt;rimary double bundles and number of intercalary bundles demonstrated 

 ere within seedlings of one class with regard to external structure is also 

 Ivident when we pass from a type of seedling with a smaller to one with a 

 igher number of primary double bundles. It has been shown in an earlier 

 taper that (a) the number of trimerous seedlings having intercalary bundles 

 generally smaller than the number of dimerous seedlings with these 

 .ccessory structures, and that (b) the average number of intercalary bundles 

 s generally smaller in trimerous than in dimerous seedlings. 



L/A/E 93 



i/NE 14-3 



0/2 

 LJ/VE 139 



/ 



DIAGRAM 2. 



3U/VULES 



Regression of number of primary double bundles on number of intercalary 

 bundles, at base of hypocotyl. 



2. Relationship between the Total Number of Bundles and the Number of 

 Bundles of the Two Types. We may now inquire to what extent the varia 

 tion in the total number of bundles depends upon the primary double 

 bundles and to what extent upon the number of intercalary bundles. As a 

 first step we determine the correlation between the total number of bundles 

 and the number of primary double bundles, and between the total number 

 of bundles and the number of intercalary bundles. These results are set 

 forth in table 2. 



We note that the correlations between the total number of bundles and 

 the number of intercalary bundles are in all cases high, ranging from + .42 



