358 



AMERICAN JOURNAL OF BOTANY 



[Vol. 8, 



and epicotyls of the normal and abnormal seedling, i.e., of dimerous and 

 trimerous seedlings, from the same parent plants are given in table y. 6 



TABLE 7. Correlations between bundle number in offspring of same parent plant 



Character of Plant and 

 Organs Compared 



Line and Correlation 



The coefficients are low throughout. Nine of the 12 are positive while 

 3 are negative in sign. Only 2 of the 12 can be reasonably regarded as 

 significant. Both of these are positive. There is, therefore, a suggestion 

 of a positive correlation between the anatomical characters of seedlings 

 from the same parent. The values are too low, however, to justify the 

 conclusion that there is a measurable differentiation in the genetic or 

 physiological characteristics of the parent plants affecting bundle number 

 in the offspring seedling. 



The absence of correlation here connotes an absence of (sororal or fra 

 ternal) inheritance in bundle number. 



SUMMARY 



In an earlier paper we have shown that the number of vascular elements 

 at different levels in the seedling of Phaseolus vulgaris is subject to consider 

 able variation and that the amount of variation may itself differ from level 

 to level. This is true both in normal seedlings with two cotyledons and 

 two primordial leaves and in variant seedlings with three cotyledons and 

 a whorl of three primordial leaves. These two types of seedlings are pro 

 foundly differentiated in vascular anatomy as well as in superficial structure. 



The purpose of the present paper is to consider the correlations between 

 the number of bundles in the various regions of the seedling. The characters 

 considered are (i) number of primary double bundles, of intercalary bundles, 

 and of total bundles at the base of the hypocotyl, (2) number of bundles in 

 the central region of the hypocotyl, and (3) number of bundles in the central 

 region of the epicotyl. 



i. There is a substantial correlation between each of the three classes 

 of bundles at the base of the hypocotyl and the number of bundles in the 

 central region of the hypocotyl. In the normal seedlings the coefficients 



6 It has not seemed worth while to publish the tables upon which these very slight 

 correlations are based. For purposes of comparison the series sectioned at Cold Spring 

 Harbor and at Storrs are both given. 



