8o 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
the total number of bundles at the base of the hypocotyl, it therefore 
becomes a question as to whether we should count each primary double 
bundle as a single strand or as a double strand; adding, of course, the 
number of intercalary bundles in each case. 
The distribution of total bundle number at this level according to the 
former method (primary double bundles counted as one, plus intercalaries) 
is shown in table 7, for both dimerous and trimerous seedlings. The 
results are shown clearly in figure 15.^ The modal number is on 4 (lines 
75, 98, 139, and 143) or 5 (line 93) bundles in the case of the dimerous 
seedlings, but invariably on 6 in the trimerous plantlets of the five lines. 
The distribution of number of bundles is almost wholly skew in the case 
of the normal seedlings, line 93 being slightly different from the others, but 
fairly symmetrical in the trimerous series. 
The constants given in table 8 show that on the average the trimerous 
plants have from 0.77 to 1.91 bundles more than the dimerous plants. 
This is an excess of from 14.4 to 46.7 percent instead of the 50 percent which 
one might expect if the increase in number of bundles were proportional 
to the number of cotyledons or primordial leaves. 
Table 8, Statistical constants for total number of bundles at base of hypocotyl of trimerous 
plants and their normal controls. Primary double bundles are counted as one bundle only 
Mean 
Standard Deviation 
Coefficient of Vari- 
ation 
Line 75 
Trimerous (N 142) 
Dimerous (N = 142) 
Actual difference 
Relative difference 
Line 93 
Trimerous (N = 155) 
Dimerous (N = 155) 
Actual difference 
Relative difference 
Line 98 
Trimerous (N = 183) 
Dimerous (N = 183) 
Actual difference 
Relative difference 
Line 139 
Trimerous (N = 106) 
Dimerous (N = 150) 
Actual difference 
Relative difference 
Line 143 
Trimerous (N = 221) 
Dimerous (N = 221) 
Actual difference 
Relative difference 
6.23 ±.03 
4.85 ±.06 
0.601 ±.024 
1.087 ±.044 
9.65 ± .39 
22.41 ± .94 
+ i.38±.07 
28.45 
6. II ±.02 
5-34±-o6 
-o.486±.050 
44.71 
o.434±.oi7 
i.oi9±.039 
— i2.76±i.oi 
7.io± .27 
I9.07± .76 
+0.77 ±.06 
14.41 
6.06 d=. 02 
472±.05 
-o.585±.042 
57.41 
o.365±.oi3 
0.909 ±.032 
— ii.97± .80 
6.02 ± .21 
i9.28± .70 
+ i.34±-05 
28.39 
6.00±.02 
4.09 ±.02 
-o.544±.035 
59.85 
o.307±.oi4 
o.334±.oi3 
-I3.26± .73 
5.i2± .24 
8.i5± .32 
+ i.9i±-03 
46.70 
6.io±.03 
4-38±.03 
— o.o27±.oi9 
8.08 
o.6i3±.020 
0.609 ±.020 
- 3.03 ± .40 
io.o6± .33 
13.91 ± .45 
+ i.72±.04 
39-27 
+0.004±.028 
0.66 
- 3.85± .56 
Lines 139 and 143 are in essential agreement with 75, 93, and 98, and are not drawn. 
