96 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
larger series of plantlets would result in the finding of such seedlings in 
lines 98, 139, and 143, thus bringing the five series into full agreement. 
In the trimerous seedlings the number of bundles shows rather wide, 
and fairly symmetrical, distribution about the modal class, which is 15 
bundles. The lines differ, however, to a considerable extent in the amount 
of variation from the modal class. In lines 75, 93, and 98 the frequencies 
are to a far greater extent concentrated into the modal class, which contains 
from 39 to 51 percent of the frequencies, than in line 143, which contains 
only 24 percent of the cases. Line 139 is intermediate between these two 
extremes. 
For a more precise comparison we utilize the constants set forth in 
table 16. 
Table 16, Statistical constants for number of bundles in epicotyl of trimerous and dimerous 
seedlings 
• 
Mean 
Standard Deviation 
Coefficient of 
Variation 
Line 75 
Dimerous (N = 416) 
Line 93 
Trimerous (N = 557) 
Dimerous (N = 557) 
Actual difference 
Relative difference 
Line 98 
Trimerous (N = 345) 
Dimerous (N = 345) 
Actual difference 
Relative difference 
Line 139 
Trimerous (N = 106) 
Dimerous (N = 150) 
Actual difference 
Relative difference 
Line 143 
Trimerous (N = 221) 
Dimerous (N = 221) 
Relative difference 
15.47 ±.04 
i2.27zt.O2 
i.355=b.032 
o.735zb.oi7 
8.76zb.2i 
5-99±.i4 
+3.2odb.04 
26.08 
15.65 ±.04 
12.19db.02 
+ 0.620zb.036 
84.35 
1.372 =b. 028 
0.6l5zb.OI2 
+ 2.77zt.24 
8.77zb.i8 
5.05zt.io 
+346±.04 
28.38 
14.89rb.04 
12. II dz.02 
+0.757 =b.030 
123.09 
I.I52zb.030 
0.4l6db.0II 
+ 3.72zlz.20 
7.74zb.2o 
3 44 ± -09 
+2.78zt.04 
22.96 
15.24zb.08 
12.15zb.02 
+o.736zb.032 
176.92 
i.285zb.o6o 
0.406 zt. 016 
+ 4.30zb.22 
8.44±.39 
3-35±.i3 
+3.09db.o8 
2543 
16. 10=1=. 08 
12.36zh.03 
+ 0.879 zb. 062 
216.50 
i.750ziz.056 
0.757 ±.024 
+5.09zt.4i 
10.87 zt.35 
6.i3zb.20 
+3.74zb.09 
30.26 
+o.993zb.o6i 
131. 18 
+4.74d=.40 
These results show that without exception the average number of bundles 
in the epicotyl is higher in trimerous than in dimerous seedlings. The 
difference ranges from 2.8 to 3.7 bundles. The probable errors of these 
differences are so small that there can be no reasonable doubt of their 
significance. In relative terms, the number of bundles in the abnormal 
plant is from 23.0 to 30.3 percent higher than that in the normal plant. 
