354 AMERICAN JOURNAL OF BOTANY [Vol. 8, 



number of bundles in the hypocotyl and in the mean number of bundles 



in the hypocotyl associated with variations in the epicotyl. The straight 

 line equations are as follows: 



Dimerous Trimerous 



Line 75, H = 10.325 - .o68 H = 12.055 + .ooyE 



E = 12.347 - .ooSH E = 15.267 + .oi6H 



Line 93, H = 5.736 + 4OiE H = 11.501 + .Q5oE 



E = 11.494 + .065^ E = 14.273 + .ii2H 



Line 98, H= 1.374 + .6485 ff= 11.408 + .O42E 



E = 11.388 + .078H E = 12.538 + .i 9 5# 



Line 139, H = 4.105 + -338 H = 12.492 - .O33E 



E = 11.254 + .io3# E = 16.591 - .II3-H&quot; 



Line 143, H = 6.677 + -i6iE H = 9-279 + 



E = 11.737 + .072^ E = 11.810 + 



All of these lines have been drawn, but it seems unnecessary to publish 

 more than three sets. 



The comparison between the empirical and the theoretical mean number 

 of bundles in the epicotyls of seedlings classified according to the number 

 of bundles in the hypocotyl is made for three lines on diagram 7. Con 

 versely, the comparison of the actual mean number of bundles in the hypo 

 cotyl for plants with various numbers of bundles in the epicotyl is made on 

 diagram 8. 



The slight slope of the lines and the irregularity of the empirical means 

 show in a very convincing manner the laxness of the relationship between 

 the numbers of bundles in the central regions of hypocotyl and epicotyl. 



These results are of decided morphological significance. The profound 

 difference between the correlations for the hypocotyl and for the epicotyl 

 emphasizes the completeness of the loss of individuality of the bundles at 

 the cotyledonary node. Whereas the number of bundles in the central 

 region of the hypocotyl is quite closely correlated with the number at the 

 base of the hypocotyl, there cannot be asserted to be any significant correla 

 tion in bundle number between either the base or the central region of the 

 hypocotyl and the central region of the epicotyl, when we deal with seedlings 

 of the same gross morphological structure. In other words, the reorganiza 

 tion of the vascular system at the node is so complete that the portion of the 

 system which is above the node shows practically no relation to the portion 

 which is below the node. 



Comparison of Correlation in Trimerous and Dimerous Seedlings. 



In examining the results of the preceding tables the reader may have 

 noted that the coefficients for the dimerous are preponderantly higher than 

 those for the trimerous plants. This result is clearly brought out in table 6 



