340 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8, 
problems which we propose first to consider. We shall also compare the 
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 of 
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 usual 
method of product-moment correlation. 
Presentation and Analysis of Data 
The series of data considered here are in large part the same as those 
discussed in our earlier paper, but have in some cases been supplemented 
by the examination of additional sections. These have been included when 
the dimerous and trimerous seedlings were not true siblings. In lines 75, 
93, and 98, the series compared were obtained from the same mothers. In 
so far as the data are the same as those used earlier, the variation constants 
for the different characters have already been presented and discussed and 
require no further comment here. The data from which measures of in- 
terrelationship may be computed are given in our fundamental tables A to L. 
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 of 
bundles — primary double bundles, intercalary bundles, and total bundles — 
at the base of the hypocotyl and the number in the central region of the 
hypocotyl. The reader who cares to do so may reconstruct the 24 correla- 
tion tables necessary for a consideration of these relationships from our 
fundamental tables A-L. 
Table i. Coefficients of correlation between number of primary double bundles, number of 
intercalary bundles, and total bundles at base of hypocotyl, and number 
of bundles in central region of hypocotyl 
Character of Seed- 
lings and Line 
N 
Correlation for Primary 
Double Bundles 
Correlation for 
Intercalary Bundles 
nh 
Correlation for 
Total Bundles 
Trimerous 
Line 75 
142 
+.378d=.049 
7.79 
-(-.329 ±.051 
6.51 
-f .649=b.033 
19.8 
+.233±.05i 
4-55 
+ .204=b.052 
3.92 
-f .469rb.042 
II. I 
Line 98 
183 
+.321 ±.045 
7.17 
-]-.253=b.047 
542 
-f.586rb.033 
17.9 
106 
-i-.417i.054 
7.71 
-l-.097rb.065 
1.50 
+ .53i=b.047 
II.3 
221 
4-. 556 d=. 03 1 
17.8 
-[-.305 =b. 04 1 
7.40 
+ .753rb.020 
38.3 
Dimerous 
-f .797rb.02I 
38.0 
Line 75 
142 
-t-.362rb.049 
7-35 
-f.668rb.031 
21.3 
Line 93 
-l-.64izb.032 
21.0 
-f .390rb.046 
8.50 
-f.753rb.023 
32.2 
183 
-[-.666 ±.028 
24.0 
-f .555=b.035 
I6.I 
-f.786rb.019 
41.4 
4- .344 ±.034 
10. 1 
-f.898rb.008 
II9.7 
-l-.925rb.006 
168.3 
420 
-f.530rb.023 
22.5 
-f .634dr.020 
32.2 
-f .802rb.OII 
68.5 
