Feb. 2 ,1924 
Tissue Fluids in Cotton 
293 
Thus it is clear that the Egyptian cotton contains larger quantities of 
conducting electrolytes in its leaf tissue fluids, just as it has been shown 
in the preceding section to contain larger quantities of osmotically 
active solutes. 
Comparisons between the first and the second series show that in both 
Egyptian and Upland cotton (Table XI, columns 5 and 6) the electrical 
conductivity in the second series is invariably lower than in the first 
series. The differences are in all cases over 7.2 times as large as their 
probable errors and may be considered statistically significant in every 
instance. 
The correlation between the plants of the same duplet or triplet is 
smaller in the second series than in the first. This result is in full agree¬ 
ment with that for osmotic concentration presented above. Since these 
correlations are not discussed in detail in this place, but merely served 
as a means of determining certain probable errors which are essential 
to the interpretation of the other constants, their probable errors, and 
the probable errors of the differences between them, have not been 
determined. 
The differences between the two types of cotton (Table XI, column 8) 
are in all cases greater in the second than in the first series. The differ¬ 
ences between Egyptian and Upland cotton in reciprocal ohms are over 
twice as great in the second as in the first series. 
The ratio of these differences between the differences to their probable 
errors (calculated with due regard to the correlation between the differ¬ 
ences themselves as explained above and shown in column 8) varies 
from 3.5 to 5.7 and may be reasonably considered to indicate statistically 
significant differences. 
The ratios of the differences between the Egyptian and the Upland 
plants to their probable errors (column 9) are regularly larger in the 
second than in the first series of determinations. 
Since the differences are based upon smaller absolute values in the 
second series than in the first, they are relatively larger than they appear 
to be as shown in column 8. The percentage differences in column 10 
show that in the first series of determinations the Egyptian cotton has 
from 2.9 to 3.8 per cent higher electrical conductivity than the associated 
Upland cotton. In the second series of determinations, the Egyptian 
cotton is characterized by from 8.2 to 9.2 per cent higher electrical 
conductivity of its leaf tissue fluids. 
COMPARISON ON THE BASIS OF THE RATIO OF SPECIFIC ELECTRICAL CONDUCTIVITY TO 
freezing POINT depression 
We now have to consider the relative proportion of electrolytes as 
indicated by the ratio of the specific electrical conductivity to freezing 
point lowering, k/ A. 
The comparisons between the Upland and Egyptian varieties appear 
in Table XII which is constructed on the same principle as Table X. 
For the first series the differences between the Egyptian and the Upland 
types (column 8) are in three cases positive and one case negative in 
sign. In none of these four cases is the difference as much as two 
and one-half times as large as its probable error. We must, therefore, 
conclude that the two forms have practically the same average ratios. 
