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AMERICAN JOURNAL OF BOTANY 



[Vol. 8 



tion is from 0.8 to 0.9 bundle, or from 55 to 65 percent of the larger value in 

 lines 75, 93, and 98. In line 143 the difference is only 0.4 bundle, or 36 

 percent. In line 139 there is practically no difference in the standard 

 deviation of bundle number in the mid-region of the first two internodes of 

 the seedling. 



TABLE 18. Comparison of statistical constants for number of bundles in hypocotyl and epicotyl 

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



Actual difference . . 

 Relative difference. 

 Line 98 (N = 345) 



27-33 



48.81 



[.27.22 



Basing the comparisons on the coefficient of variation, we note that the 

 coefficients for the hypocotyl range from 13.0 to 17.3 percent, whereas those 

 for the epicotyl range from 3.4 to 6.0 percent in lines 75, 93, and 98. Thus 

 there is a difference of about 10 percent in the coefficient of variation of 

 bundle number in the hypocotyl and epicotyl (of the normal seedlings) of 

 these lines. In line 143 this difference is only 7.50 percent. In line 139 

 it is only 1.69 percent. 



The statistical relationship is in full accord with the anatomical findings 

 recorded above (p. 68) where it was shown that the intercalary bundles of , 

 the hypocotyl as they approach the cotyledonary node fuse with the (nor- , 

 mally 8) bundles originating by the division of the (normally 4) protoxylem 

 poles of the primary root and completely lose their individuality, exactly 

 six bundles emerging from the complex irrespective of the number which 



