340 



AMERICAN JOURNAL OF BOTANY 



problems which we propose first to consider. We shall also compare thf 

 normal and abnormal seedlings as to the correlations which they exhibit 

 and shall touch briefly on the problem of the correlation between bundle 

 number in seedlings from the same parent plant. 



The frequency distributions of bundle number are in many cases ol 

 very narrow range and very skew. There has, therefore, been consider 

 able question as to the formulae to be employed. It has seemed best 

 for various reasons which need not be detailed here, to employ the usua 

 method of product-moment correlation. 



PRESENTATION AND ANALYSIS OF DATA 



The series of data considered here are in large part the same as thos&amp;lt; 

 discussed in our earlier paper, but have in some cases been supplements 

 by the examination of additional sections. These have been included wher 

 the dimerous and trimerous seedlings were not true siblings. In lines $ 

 93, and 98, the series compared were obtained from the same mothers. It 

 so far as the data are the same as those used earlier, the variation constant 

 for the different characters have already been presented and discussed an( 

 require no further comment here. The data from which measures of in 

 terrelationship may be computed are given in our fundamental tables A toL 

 We have, therefore, merely to deduce and discuss the correlation coefficients 



Correlation between Bundle Number at Different Levels 

 in the Same Internode 



We first turn to the problem of the relationship between the number o 

 bundles primary double bundles, intercalary bundles, and total bundles- 

 at the base of the hypocotyl and the number in the central region of th 

 hypocotyl. The reader who cares to do so may reconstruct the 24 correla 

 tion tables necessary for a consideration of these relationships from ou 

 fundamental tables A-L. 



TABLE i. Coefficients of correlation between number of primary double bundles, number &amp;gt; 

 intercalary bundles, and total bundles at base of hypocotyl, and number 

 of bundles in central region of hypocotyl 



