320 
Journal of Agricultural Research voi. xxvii. No. 5 
Table XXIV .—Comparison of the correlations for the same duplet or triplet in IQ2I> 
for the various physico-chemical properties , the values being the differences between the 
coefficients of correlation for each pair of characters 
Member of duplet or triplet be¬ 
tween which the correlation is 
determined. 
Rows. 
Difference 
between 
correla¬ 
tion for 
depres¬ 
sion of 
freezing 
point, A, 
and spe¬ 
cific elec¬ 
trical con¬ 
ductivity, 
K. 
A-k 
1 
Difference 
between 
correla¬ 
tion for 
depres¬ 
sion of 
freezing 
point, A, 
and ratio 
of conduc¬ 
tivity to 
depres¬ 
sion, Kj A. 
A-*/ A 
Difference 
between 
correla¬ 
tion for 
depres¬ 
sion of 
freezing 
point, A, 
and hy¬ 
drogen- 
ion con¬ 
centra¬ 
tion, P„ 
a-p h ' 
Difference 
between 
correla¬ 
tion for 
specific 
electrical 
conduc¬ 
tivity, K, 
and ratio 
of conduc¬ 
tivity to 
depres¬ 
sion k/A. 
k-k/A 
Difference 
between 
correla¬ 
tion for 
specific 
electrical 
conduc¬ 
tivity, K, 
and hy¬ 
drogen- 
ion con¬ 
centra¬ 
tion, P„ 
K- P 
Difference 
between 
correla¬ 
tion for 
ratio of 
conduc¬ 
tivity to 
depres¬ 
sion, k/A, 
and hy¬ 
drogen- 
ion con¬ 
centra¬ 
tion ,p H 
*/A-p H ’ 
First series: 
Pima and Meade. 
-f 0.1829 
+0.4273 
+0.4538 
+0. 2443 
I 
+0. 2708 
+0.0265 
Do. 
3*7 
+. 0887 
+• 2633 
+ • 5349 
+. 1746 
+• 4462 
+. 2716 
Do. 
L 3 > 5*7 
+• 1309 
+.3624 
+ •4738 
+• 2315 
+• 3430 
+• 1115 
Pima and Acala. 
2*4*6 
+• 1974 
+. 2969 
+ . 6320 
+.0995 
+. 4346 
+- 335 I 
Hybrid and Pima. 
i *5 
+■ 1577 
+•3783 
+• 5672 
+. 2206 
+•4095 
+.1889 
Do. i 
3*7 
+•3755 
+• 6550 
+. 1408 
+. 2794 
-• 2347 
—• 5142 
Do. 
1 - 3 * 5 * 7 
+.3266 
+• 5241 
+ •4307 
+• 1975 
+. 1041 
—•0934 
Hybrid and Meade. 
1*5 
+. 2428 
+. 4087 
+• 6741 
+• 1659 
+• 43 i 4 
+• 2655 
Do. 
3 * 7 
+. 2996 
+.4483 
+. 3896 
+. 1487 
+. 0901 
— . 0586 
Do. 
, i* 3 * 5 ? 7 
+. 2948 
+. 4768 
+ • 5790 
+. 1821 
+• 2843 
+. 1023 
Second series: 
Pima and Meade. 
1*5 
+ . 4010 
+ •6545 
+ . 2074 
+ •2535 ! 
— .1936 
—.4470 
Do. 
3> 7 
+ .3772 
+.0917 
+. 0462 
• 2855 j 
—•3310 
-• 0455 
Do. 
** 3> 5 * 7 
+ .3638 
+•4033 
+ . 1692 
+ •0395 I 
— . 1946 
-• 2341 
Pima and Acala. 
2,4* 6 j 
1 +.2273 
+. 2282 
+. 1170 
+ • 0009 { 
—• 1103 
— .1112 
Hybrid and Pima. 
i *5 
+ • 1550 
+. 6289 
+. 1149 
+.4738 
— . 0401 
—• 5139 
Do. 
3 * 7 
+ •3047 
+. 1610 
— . 0145 
-•1437 
—•3193 
-• 1755 
Do. 
I* 3 ’ 5 * 7 
+ . 2064 
+.4187 
+ . 0748 
+. 2123 ! 
—• 1316 
-•3439 
Hybrid and Meade. 
i *5 
+ . 5040 
+ •9494 
+ .4942 
+•4554 i 
— . 0098 
-• 4552 
Do. ! 
3*7 
+ . 5162 
+• 4995 
— . 1615 
-. 0166 J 
— . 6776 
— . 6610 
Do. 
i* 3 * 5-7 
+ . 4806 
+ • 7072 
+ ■ 1545 
+• 2265 j 
— . 3262 
-•5537 
For further evidence on this point we may turn to Table XXI, 
showing the correlation between the various constants in the first and 
second series. 26 The coefficients for the Upland and hybrid series have 
been shown to be so nearly zero that they may be disregarded for the 
moment. Considering the more substantial values of the correlation 
for the Egyptian cotton, it appears that the highest values found are 
those for A, which are of the order 0.40. The correlations for k and 
k/A are of the order 0.30. The correlations for P H are sensibly zero. 
These results seem to indicate that the absorption of electrolytes from 
the soil is not the most important, or at least the sole, factor in the differ¬ 
entiation of the plants. This is shown by the fact that the correlations 
for osmotic concentration are higher than those for electrical conducti¬ 
vity and for ratio of conductivity to freezing-point lowering. That 
synthesized solutes are of importance in differentiating the plants of the 
same duplet or triplet at the moment at which the collection is made, is 
shown by the substantial values of the correlations for hydrogen-ion 
concentration between the members of the same duplet or triplet, as 
demonstrated for the Egyptian and Upland plants in the seventh column 
of Table XIII and for the parental and the hvbrid types in the seventh 
column of Table XVIII. 
It is perhaps not surprising that the correlation for total solutes should 
be higher than that for either of its measured constituents. 
26 In view of the fact that we hope later to discuss in detail the problem of the relationship between the 
properties of the soil solution and those of the plant tissue fluids, it seems undesirable to consider the cross 
correlations between the first and second series of constants as set forth in Table XXII. 
