Feb. a,1924 
Tissue Fluids in Cotton 
299 
the progenies of the two individual parents of the hybrid, Pima (27), 
and Acala (28). 
The constants are set forth in table XIV. 
Table XIV. —Physicochemical constants for the leaf tissue fluids of the F y hybrid 
between Egyptian and Upland cotton grown in IQ20 , and differences between con¬ 
stants for the hybrid and those for the parent types 
Type and varieties compared. 
Fi hybrid, Acala UplandXPima Egyptian. 
Difference between Fi hybrid and Pima Egyp¬ 
tian. 
D iff pence between Fi hybrid and Acala Upland. 
Fi hybrid, Pima Egyptian X Upland. 
Pima Egyptian. 
Difference between Fi hybrid and Pima Egyp¬ 
tian . 
F1 hybrid, Pima Egyptian X Upland. 
Holdon Upland. 
Difference between Fi hybrid and Holdon 
Upland. 
Fi hybrid, Pima Egyptian X Upland. 
Difference between Fi hybrid and Pima Egyp¬ 
tian... 
Difference between Fi hybrid and Holdon 
Upland. 
Fi hybrid, Acala UplandXPima Egyptian. 
Difference between Fi hybrid and Pima Egyp¬ 
tian . 
Difference between Fi hybrid and Acala Upland. 
i 
i 
Sample 
number.® 
Depres¬ 
sion of 
freezing 
point, 
A 
Osmotic 
concen¬ 
tration 
in atmos¬ 
pheres, 
P. 
Specific 
electrical 
conduc¬ 
tivity, 
K. 
Ratio of 
conduc¬ 
tivity to 
depres¬ 
sion, 
kJA . 
I (29) 
J 1.124 
13 - 53 
| 0.03316 
0.03000 
(29M1) 
(29M2) 
(30) 
(31) 
-0.268 
—0.094 
1-295 I 
1-365 j 
- 3-21 
— 1.12 
15.58 
16. 42 i 
j —.OO564 
i 4 -. 00233 
! • 03015 
.03162 
4 - -00213 
4-. 00468 
.02328 
.02317 
(30M31) 
(32) 
(33) 
i 
^0.070 ; 
1.496 ! 
1.468 } 
—0.84 : 
17-99 
17-65 : 
— .00147 
•03132 
• 03222 
4-.00011 
.02093 
.02195 
(32M33) 
(34) 
+0.028 J 
1.327 ; 
4-0.34 
15.96 
— .00090 
. 05141 
—.00102 
- 03874 
(34M25) 
—0.020 ! 
—0.-4 j 
— .00433 
—.00263 
(34M26) 
(35) j 
4-0.077 , 
1.087 : 
4-0.92 j 
13-08 i 
— .00013 
.02801 
—.00249 
•02578 
(35H.27) i 
(35M28) I 
i 
— O. l66 : 
—0.026 ! 
1 
—1.99 
—0.32 
—.00408 
+ . 00007 
4 * .00017 
+.00068 
° Constants for parental forms not given in this table appear under these numbers in Table I. 
These results show that in all four comparisons between Egyptian 
cotton and the hybrid between Egyptian and Upland cotton the osmotic 
concentration is higher in the leaf-tissue fluids of the Egyptian than in 
those of the hybrid plants. In all four comparisons, the specific 
electrical conductivity indicates that there is a higher concentration of 
conducting electrolytes in the tissue fluids of the Egyptian than in those 
of the hybrid plants. In three of the four comparisons the ratio k/A is 
higher in the hybrid than in the Egyptian cotton. 
The results of the comparisons between the hybrid and the Upland 
cottons are more irregular. Since both hybrid and Upland cottons 
seem to differ from Egyptian cotton in the same direction, it is only 
natural to find that there is not such a conspicuous difference between 
hybrid and Upland as between hybrid and Egyptian. 
The results of this preliminary study can not be taken as conclusive. 
They are, however, suggestive, and fully justified the more intensive 
investigation undertaken in 1921. 
investigations in 1921 
COMPARISONS ON THE BASIS OF FREEZING-POINT DEPRESSION 
A comparison of the freezing-point depressions of the tissue fluids of 
the hybrid with its two parent forms appears in Table XV. 
This table (which may serve as a type for the others of this section) 
is prepared as follows: The forms compared with the hybrid are given 
