16,5 Espino: Salt Requirements of Young Rice Plants 513 
may be compared, and especially since the amount of water ab- 
sorption is much more easily determined for solution cultures 
than is any other quantitative plant value, it seemed desirable 
to make these water-absorption determinations in the present 
study. 
The data in Table 13 show that the highest values are not 
generally found for the two medium total concentrations as was 
the case for dry yield and green weight. It is commonly under- 
stood that, except in special cases, the lower the total concentra- 
tion the higher the rates of water absorption and transpiration, 
providing that the plants to be compared are all fairly healthy, 
and that all have been exposed to the same set of non-solution con- 
ditions. In spite of this consideration, however, the very highest 
water-absorption values for the one hundred forty simultaneous 
cultures here dealt with are for the low-medium total concentra- 
tion (solutions TIRISI and T2R2S2). The highest total con- 
centration here considered generally gives values lower than the 
corresponding ones of the other three total concentrations. 
Without trying to determine which one of the solutions may be 
expected to show the highest absorption rates, we may turn 
to the two medium total concentrations and make a comparison 
between their group designations (H and L) and those obtained 
from these two total concentrations in terms of dry yield and 
green weight of tops. 
Such a comparison may be instituted by means of Table 
14, which is a reproduction of Table 12 with the water-absorp- 
tion designations added as a third column for each series. 
The method followed is the same as was used for Table 12, and 
the notation is the same throughout. 
Examination of Table 14 shows that the group designations 
for water absorption generally agree with those for green weight, 
and in the majority of cases agreement is perfect for all three 
criteria. In each of these four series there are from five to eight 
discrepancies between the evidence from green weight and that 
from water absorption, but there seems to be no relation between 
the number of discrepancies and the total concentration, unless 
such evidence may be suggested by the fact that series 16 (with 
the low-medium concentration) shows only five disagreements 
of this kind, while series 14 and 20 show seven each, and series 
19 shows eight. It may be concluded immediately that water 
absorption is apparently just as satisfactory in discriminating 
between the different cultures of any series as is either dry 
yield or green weight. All three criteria appear to be about 
equally valuable. 
