Nov., 1921] 
HARRIS AND OTHERS — PHASEOLUS VULGARIS 
427 
Dimerous 
Trimerous 
Line 75 : 
P 
I 
P 
I 
P 
I 
P 
I 
P 
I 
4.255 - 0.058 / 
I.641 — 0.239 P 
4.607 — O.I 10 / 
1.398 — 0.127 p 
4.099 + 0.035 / 
0.II4 + 0.II7 p 
4.005 + 0.034 1 
p 
I 
p 
I 
p 
I 
p 
I 
p 
I 
6.059 
4.968 
5.992 
5.200 
5-984 
6.559 
5.958 
2.795 
5.924 
1.732 
0.318/ 
0.789 P 
0.448 / 
0.846 P 
0.392 I 
1.084 P 
0.558 / 
0.457 P 
0.408 I 
0.24c) P 
Line 93 : 
Line 98: 
Line 139: 
- 2.038 + 0.541 P 
Line 143: 
4.060 + 0.019 / 
0.047 + 0.059 P 
The mean number of intercalary bundles associated with given numbers 
of primary double bundles and the theoretical means as given by the 
regression straight lines are shown on diagram i. 
For the normal plants of lines 75, 93, and 139 the agreement between 
the observed means and the regression line is very satisfactory. In line 
98 a single seedling with 8 primary double bundles and 4 intercalary bundles 
gives a positive sign to the correlation and makes the agreement of theo- 
retical and empirical means very poor indeed. In lines 139 and 143 the 
correlation is also positive. It must be noted that we are dealing here 
with a very narrow range of both primary double bundles and intercalary 
bundles, and with very small frequencies in some of the classes. 
For the abnormal plants the agreement of empirical means and theo- 
retical lines is apparently very poor indeed. This is perhaps largely attrib- 
utable to two facts: 
(a) The frequencies of primary double bundles are, practically speaking, 
concentrated in two classes, 5 and 6 bundles. From 93 to 99 percent of the 
seedlings fall in these two classes. As a result of this condition, the ob- 
taining of trustworthy averages for the extreme classes of primary double 
bundles is, practically speaking, impossible. 
(b) The influence of the two principal classes (5 and 6) of primary 
double bundles is such as to throw the theoretical mean number of interca- 
lary bundles for higher classes of primary double bundles on the negative 
side of o in four of the five cases. 
As a consequence, the actual mean number of intercalary bundles must 
lie above the line in all cases in which more than 6 primary double bundles 
are formed. 
Whether these irregularities represent a significant deviation from line- 
arity can be determined only when far larger series of data are available. 
While the primary double bundles must probably be regarded as more 
fundamental structures than the intercalary bundles, it seems of interest to 
determine the mean number of primary double bundles associated with each 
number of intercalary bundles. 
